Mountains, Rivers & Oceans

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Mauna Kea, a Hawaiian volcano, rises more than 10,210 meters (33,500 feet) from its base on the Pacific seafloor to its summit, yet only about 4,200 meters of it show above the waves. Mount Everest, at 8,848 meters, is the highest peak above sea level, which is why it feels like the obvious answer, but measured base-to-peak it is well over a kilometer shorter. K2 tempts as Everest's famous runner-up, yet it too is ranked by elevation above sea level. Denali really does boast one of the greatest base-to-peak rises on dry land, but even that is roughly half of Mauna Kea's full height. The lesson: 'highest' and 'tallest' are two different records, and the tallest mountain on Earth is mostly invisible.

Source: NOAA Ocean Service: 'What is the highest point on Earth as measured from Earth's center?' (oceanservice.noaa.gov/facts/highestpoint.html)

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The Challenger Deep, at the southern end of the Mariana Trench in the western Pacific, measures about 10,935 meters (35,876 feet) deep according to NOAA. That is so deep that if Mount Everest were dropped in, its summit would still sit roughly two kilometers underwater. The Tonga Trench is the great near-miss: its deepest point, Horizon Deep, is only on the order of a hundred meters shallower, making it a genuinely tempting pick. The Puerto Rico Trench is merely the deepest point of the Atlantic, and the Java Trench the deepest of the Indian Ocean, so each is a record-holder in its own basin without coming close to the Mariana's crushing bottom, where the water pressure exceeds a thousand times that at the surface.

Source: NOAA Ocean Service: 'How deep is the ocean?' (oceanservice.noaa.gov/facts/oceandepth.html)

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The Nile, flowing about 6,650 kilometers through northeastern Africa, holds the top spot in most reference works — but the record is genuinely contested, and that contest is the real story. The Amazon is the tempting rival for good reason: it carries far more water than any other river on Earth, and a 2007 Brazilian expedition, tracing a more distant southern source, measured it at nearly 7,000 kilometers, which would edge out the Nile. Because a river's 'length' depends on which headwater and which mouth you choose, the two effectively share a disputed crown, with the Nile keeping the traditional title. The Yangtze is Asia's longest river and ranks third worldwide, while the Mississippi–Missouri system, North America's longest, sits fourth — neither contends for first.

Source: Encyclopaedia Britannica: 'Nile River' and 'How Long Is the Amazon River?' (britannica.com/place/Nile-River)

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Antarctica's interior receives fewer than five centimeters of precipitation a year, which makes the ice-covered continent — at roughly 14 million square kilometers — the largest desert on the planet. The Sahara is the answer almost everyone reaches for, and it truly is the largest hot desert, but at about 8.6 million square kilometers it covers well under two-thirds of Antarctica's area. The Gobi and the Arabian Desert both rank among the biggest deserts on Earth, which makes them plausible-sounding picks, yet each is far smaller than the Sahara, let alone Antarctica. The counterintuitive punchline is that the driest, emptiest desert on Earth is made of ice: precipitation, not temperature, is what earns a landscape the name.

Source: Encyclopaedia Britannica: 'World's largest deserts' (britannica.com/topic/worlds-largest-deserts-2225895)

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Lake Baikal in Siberia is the world's deepest lake, plunging more than 1,600 meters, and also its oldest, at an estimated 20 to 25 million years. The astonishing payoff: that single rift-valley lake holds about one-fifth of all the fresh water on Earth's surface. Lake Tanganyika is the classic near-miss, since it genuinely is the second-deepest lake on the planet, roughly two hundred meters shallower. The Caspian Sea tempts because it is the largest lake on Earth by surface area — a 'sea' in name only — but it is broad rather than deep. Lake Superior, the largest freshwater lake by surface area, reaches only around 400 meters at its deepest, roughly a quarter of Baikal's depth. Surface area and depth are very different records.

Source: Encyclopaedia Britannica: 'Lake Baikal' (britannica.com/place/Lake-Baikal)

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The mid-ocean ridge system stretches nearly 65,000 kilometers around the globe, winding between the continents like the seam on a baseball — yet more than 90 percent of it lies hidden in the deep ocean, where new crust is continuously born as tectonic plates pull apart. The Andes are the tempting textbook answer because they genuinely are the longest mountain range on land, running the entire western edge of South America, but even they reach only a fraction of the ridge system's length. The Himalayas boast the highest peaks on Earth while forming a comparatively short chain, and the Rocky Mountains are shorter than the Andes. The planet's greatest mountain range is one that almost no human being has ever laid eyes on.

Source: NOAA Ocean Service: 'What is the longest mountain range on earth?' (oceanservice.noaa.gov/facts/midoceanridge.html)

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Earth is not a perfect sphere — its spin makes it bulge at the Equator. Mount Chimborazo in Ecuador sits just one degree south of the Equator, right on that bulge, so its summit lies more than 2,000 meters farther from Earth's center than Everest's, even though Chimborazo's altitude above sea level is far lower. NOAA notes this makes Chimborazo, in a sense, the closest point on Earth to the stars. Mount Everest is the natural pick because it is the highest summit above sea level, but sea level itself bulges outward with the planet, so the reference line moves. Mauna Kea holds a different record entirely — tallest mountain measured base-to-peak — while K2, the second-highest peak above sea level, sits too far north of the bulge to compete.

Source: NOAA Ocean Service: 'What is the highest point on Earth as measured from Earth's center?' (oceanservice.noaa.gov/facts/highestpoint.html)

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The U.S. Geological Survey puts the average spreading rate along the Mid-Atlantic Ridge at about 2.5 centimeters per year — roughly the pace at which human fingernails grow. The payoff is what patience does with that crawl: 2.5 centimeters a year adds up to 25 kilometers every million years, enough to have opened the entire Atlantic Ocean basin over geologic time. The figure of 2.5 millimeters per year sounds suitably geological but is ten times too slow, while 25 centimeters per year overshoots even the fastest-spreading ridges in the Pacific, which manage only around 15 centimeters. A rate of 2.5 meters per year would visibly redraw the map within a single human lifetime — dramatic, but wrong by two orders of magnitude.

Source: USGS, This Dynamic Earth: 'Understanding plate motions' (pubs.usgs.gov/gip/dynamic/understanding.html)

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Scientists from NOAA and the Woods Hole Oceanographic Institution used satellite measurements in 2010 to calculate an average ocean depth of 3,682 meters — about 3.7 kilometers, roughly twice the depth of the Grand Canyon. The figure near 11,000 meters is the classic trap: that is the ocean's maximum depth, at the Challenger Deep in the Mariana Trench, not its average. Guesses around 1,200 meters or 800 meters feel reasonable because nearly all familiar marine life, diving records, and underwater photography come from the sunlit and twilight layers above 1,000 meters — but that thin, bright zone is the exception, not the rule. The typical patch of seafloor sits in permanent darkness kilometers down, which is a big part of why so much of the deep ocean remains unexplored.

Source: NOAA Ocean Exploration: 'How deep is the ocean?' (oceanexplorer.noaa.gov/facts/ocean-depth.html)

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The Pacific is the giant of the world ocean: NOAA describes it as by far the largest and deepest of the ocean basins, covering approximately 63 million square miles and holding more than half of the free water on Earth. The scale is genuinely hard to picture — all of the world's continents could fit inside the Pacific basin. The Atlantic is the tempting runner-up because it borders so many familiar coastlines and carries so much shipping, but it is only about half the Pacific's size. The Indian Ocean ranks third, and the Arctic — the smallest and shallowest of the major basins — trails far behind. Fittingly, the deepest single point on the planet, the Challenger Deep in the Mariana Trench, also belongs to the Pacific.

Source: NOAA Ocean Service: 'What is the largest ocean basin on Earth?' (oceanservice.noaa.gov/facts/biggestocean.html)

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Greenland covers roughly 2,166,000 square kilometers, making it the largest body of land on Earth that reference works still classify as an island. New Guinea is the genuine runner-up, the second-largest true island, at under half Greenland's area. Borneo ranks third among islands, smaller still. Australia is the tempting trap here: it is comparable in scale and often pictured as 'just a very large island,' but geographers and standard references classify it as a continent in its own right rather than an island, precisely because of its size and the fact that it sits on its own continental plate rather than being a fragment of a larger landmass. That classification line, not raw square kilometers, is what keeps Australia off the island leaderboard entirely.

Source: Encyclopaedia Britannica: 'The Largest Islands in the World' (britannica.com/list/the-largest-islands-in-the-world)

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Angel Falls, on Venezuela's flat-topped Auyán-tepui plateau, plunges 979 meters in total, including a single uninterrupted drop of about 807 meters — the longest unbroken fall of water anywhere on the planet, so sheer that much of the water turns to mist before reaching the base. Victoria Falls is a tempting rival because of its sheer power and width, but its drop is only around 108 meters, a fraction of Angel Falls' height. Niagara Falls is the most famous waterfall in North America and moves an enormous volume of water, yet its drop is a modest 50-odd meters, dwarfed by both other options. Tugela Falls is the genuine near-miss: its total height across multiple tiered leaps rivals Angel Falls, but because that height is broken into several separate drops rather than one continuous plunge, no single stage comes close to Angel Falls' record.

Source: Encyclopaedia Britannica: 'Angel Falls' (britannica.com/place/Angel-Falls)

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The Yangtze runs about 6,300 kilometers from the Tibetan Plateau to the East China Sea without ever crossing a national border, making it the longest single-country river on Earth as well as the longest river in Asia. The Mississippi, measured as its own main stem, flows entirely within the United States too, but at roughly 3,700 kilometers it is little more than half the Yangtze's length. The Volga is the genuine regional champion, the longest river confined to a single country in Europe, yet at about 3,530 kilometers it is dwarfed by its Asian counterpart. The Amazon is the trap for anyone thinking only of total length or water volume: despite being the largest river on Earth by discharge, it gathers tributaries across Peru, Colombia, and Brazil, so it fails the single-country test entirely regardless of its overall length.

Source: Encyclopaedia Britannica: 'Yangtze River' (britannica.com/place/Yangtze-River)

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The shoreline of the Dead Sea sits over 430 meters below sea level, the lowest point of dry land anywhere on the planet — and the payoff is that the figure keeps getting more extreme, since evaporation and upstream water diversion shrink the lake and drop its surface further almost every year. Death Valley is the classic decoy because it holds its own well-known record, the lowest point in North America, but that point is only about 86 meters below sea level, a small fraction of the Dead Sea's depth. The Qattara Depression is a real and substantial low-lying basin in Egypt's Western Desert, genuinely one of the deepest depressions on the African continent, yet it bottoms out at only around 133 meters below sea level. The Turpan Depression is Asia's own notable low point, but at roughly 154 meters below sea level it still falls far short of the Dead Sea's basin.

Source: Encyclopaedia Britannica: 'Dead Sea' (britannica.com/place/Dead-Sea); NOAA

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Ojos del Salado, a stratovolcano on the Chile-Argentina border in the Andes, rises to about 6,893 meters, making it the highest volcano anywhere on Earth. Mount Kilimanjaro is the tempting pick because it is Africa's tallest peak and one of the most famous volcanoes in the world, yet its summit reaches only about 5,895 meters, over a kilometer short. Cotopaxi is a genuine near-miss: it is regularly cited among the highest active volcanoes on the planet, but its roughly 5,897-meter summit still trails Ojos del Salado by nearly a kilometer. Mauna Loa is the real trap for anyone thinking in terms of sheer size rather than summit elevation — measured from its base on the Pacific seafloor it is the most massive volcano on Earth by volume, but as a broad, gently sloping shield volcano its summit sits at only about 4,169 meters above sea level, far lower than a steep-sided Andean peak.

Source: Encyclopaedia Britannica: 'Mount Ojos del Salado' (britannica.com/place/Mount-Ojos-del-Salado)

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The Great Rift Valley, formally the East African Rift System, stretches roughly 6,400 kilometers from Jordan and the Red Sea down through East Africa to Mozambique, making it the longest rift on land anywhere in the world — and, fittingly, the very ground where some of the oldest known human ancestor fossils have been found, since the valley's shifting terrain repeatedly exposed and preserved them. The Basin and Range Province in the western United States is a genuine large-scale zone of continental stretching, made up of many parallel fault-block mountains and valleys, but it is a broad province of extension rather than one continuous rift of comparable length. The Rhine Graben is a textbook rift valley running through Germany and France, real and well-studied, but only a few hundred kilometers long. The Baikal Rift Zone in Siberia is famous for holding the world's deepest lake, yet the rift itself is far shorter than its East African counterpart.

Source: Encyclopaedia Britannica: 'East African Rift System' (britannica.com/place/East-African-Rift-System)

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The Ring of Fire is a horseshoe-shaped belt of oceanic trenches and volcanic arcs that partly encircles the Pacific basin, running from South America up through Central America, North America, across to Russia and Japan, and down through Southeast Asia to New Zealand; USGS attributes about 90% of the world's earthquakes and most of its active volcanoes to this single zone, where the Pacific Plate grinds against its many neighbors. The Alpide Belt is the genuine second-place seismic zone, running from Java through the Himalayas to the Mediterranean, and it is a real near-miss since it accounts for a meaningful share of the planet's largest earthquakes, just far less than the Pacific belt. The Andean Volcanic Belt is a real and significant chain of volcanoes, but it is only the South American segment of the larger encircling belt, not the whole ring itself. The mid-ocean ridge system is an enormous undersea mountain chain in its own right, but it marks where plates pull apart rather than where they collide, so it is not the earthquake-and-volcano belt described here.

Source: USGS: 'This Dynamic Earth' (pubs.usgs.gov/gip/dynamic/fire.html)

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The Amazon's drainage basin covers roughly 6 to 7 million square kilometers of South America, gathering water from the Andes to the Atlantic and making it by far the largest river basin on Earth, one that alone carries about a fifth of all the freshwater that runs off the planet's land into the ocean. The Congo basin is the genuine runner-up and Africa's own giant, but at around 3.7 million square kilometers it covers roughly half the Amazon's footprint. The Mississippi basin is enormous by North American standards, draining about 40% of the continental United States, yet it still totals only around 3.2 million square kilometers. The Nile is the trap for anyone reasoning from the river's famous length rather than its catchment: despite flowing further than any other single river, much of its course threads through narrow desert corridor rather than a broad watershed, leaving its basin at only a modest fraction of the Amazon's size.

Source: Encyclopaedia Britannica: 'Amazon Basin' (britannica.com/place/Amazon-Basin)

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The Antarctic Circumpolar Current is the only current on the planet that flows all the way around the globe without ever being blocked by a continent, because at Antarctica's latitude there is an unbroken ring of open ocean; NOAA describes it as the dominant circulation feature of the Southern Ocean for exactly this reason. The Gulf Stream is a powerful and famous warm-water current, but it is confined to the North Atlantic, hemmed in by the Americas on one side and Europe and Africa on the other. The Kuroshio Current plays a similar role to the Gulf Stream but in the North Pacific, carrying warm water past Japan, yet it too is boxed in by surrounding landmasses. The Humboldt Current runs along the west coast of South America and strongly shapes the climate and fisheries there, but it is a regional coastal current rather than one that circles the entire Earth.

Source: NOAA Atlantic Oceanographic and Meteorological Laboratory: 'Antarctic Circumpolar Current' (aoml.noaa.gov/phod/altimetry/cvar/acc/index.php)

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The Bay of Bengal, the northeastern arm of the Indian Ocean bordered by India, Bangladesh, Myanmar, and Sri Lanka, covers roughly 2.2 million square kilometers, making it the largest bay on Earth by area. The Gulf of Mexico is the natural rival to consider, since gulfs and bays are both large curved indentations of a coastline and it is itself one of the largest bodies of its kind in the world, but at under 1.6 million square kilometers it still falls well short. Hudson Bay is an enormous inland sea covering much of northeastern Canada, genuinely vast at over a million square kilometers, yet still smaller than the Bay of Bengal. The Great Australian Bight is a huge open indentation along Australia's southern coastline and is often pictured on maps as similarly massive, but it covers a far smaller area than any of the other options here.

Source: Encyclopaedia Britannica: 'Bay of Bengal' (britannica.com/place/Bay-of-Bengal)

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The Caspian Sea, bordered by five countries in Central Asia, covers roughly 371,000 square kilometers, making it the largest lake on Earth by surface area, nearly four times the size of the next-largest lake. Despite the name, it is a landlocked body of saline water with no connection to any ocean, which is exactly why geographers classify it as a lake rather than a true sea. Lake Superior is the tempting answer because it genuinely is the largest freshwater lake by surface area, but at about 82,000 square kilometers it is a small fraction of the Caspian's size. Lake Victoria is Africa's largest lake and a famous source of the Nile, yet it covers only about 69,000 square kilometers. Lake Baikal in Siberia holds the separate record for deepest and oldest lake on Earth, but its surface area, at roughly 31,500 square kilometers, is modest next to the Caspian's enormous footprint.

Source: Encyclopaedia Britannica: 'Caspian Sea' (britannica.com/place/Caspian-Sea)

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Victoria Falls, on the Zambia-Zimbabwe border, is recognized as the largest sheet of falling water on Earth because of its combined width and height: at roughly 1,708 meters wide and about 108 meters tall, no other waterfall matches that product of the two dimensions, which is why locals call it Mosi-oa-Tunya, 'the smoke that thunders,' for the spray visible for kilometers. Iguazu Falls, on the Argentina-Brazil border, is the largest waterfall complex on Earth, spread across nearly 275 separate drops, but no single uninterrupted curtain there approaches Victoria Falls' combined scale. Angel Falls in Venezuela holds a different record entirely, the longest unbroken single drop of any waterfall, but it is comparatively narrow, so it cannot claim the 'largest sheet' title. Niagara Falls is iconic and carries an enormous volume of water, yet both its height and width fall well short of Victoria Falls' record-setting combination.

Source: UNESCO World Heritage Centre: 'Mosi-oa-Tunya / Victoria Falls' (whc.unesco.org/en/list/509)

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The Yarlung Tsangpo Grand Canyon in Tibet reaches a maximum depth of about 6,000 meters where the river bends sharply around the peaks of Namcha Barwa and Gyala Peri, making it the deepest canyon on Earth; it is also slightly longer than Arizona's Grand Canyon. The Grand Canyon, carved by the Colorado River, is the famous reference point for canyon scale and is itself immense, but its depth of roughly 1,800 meters is less than a third of the Yarlung Tsangpo canyon's maximum. Peru's Colca Canyon and Cotahuasi Canyon are both genuine deep-canyon contenders, each reaching roughly 3,300 to 3,500 meters and often cited as among the deepest in the Americas, but both still fall well short of the Tibetan canyon's record depth. The comparison is a reminder that tectonic uplift, not just river erosion over time, is what drives a canyon to such extremes, since the Yarlung Tsangpo river is actively cutting through some of the fastest-rising terrain on the planet.

Source: NASA Jet Propulsion Laboratory: 'Yarlung Zangpo Grand Canyon, Tibet' (jpl.nasa.gov/images/pia15775-yarlung-zangpo-grand-canyon-tibet)

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Salar de Uyuni, high in the Bolivian Andes at an elevation of about 3,650 meters, covers roughly 10,000 square kilometers, making it the largest salt flat on Earth; it formed as the prehistoric Lake Minchin evaporated over tens of thousands of years, leaving behind a crust of salt up to 10 meters thick in places. The Bonneville Salt Flats in Utah are famous worldwide for land-speed-record attempts, but at only around 260 square kilometers they are a tiny fraction of Uyuni's size. The Danakil Depression in Ethiopia is a genuinely extreme landscape, one of the hottest and lowest places on Earth with active salt pans, but its salt-flat area is far smaller than Uyuni's. Chott el Djerid in Tunisia is a large seasonal salt lake that makes a striking, shimmering landscape, but it too covers a much smaller area than Bolivia's record-holding flat.

Source: Guinness World Records: 'Largest salt flat' (guinnessworldrecords.com/world-records/82679-largest-salt-flat)

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The Bay of Fundy has the highest tidal range in the world, averaging around 16 meters at its head near Burntcoat Head, Nova Scotia, a result of the bay's long, narrowing, funnel-like shape combined with the natural resonant period of its water mass matching the rhythm of the Atlantic tide. That resonance amplifies the normal rise and fall of the ocean into a surge large enough to strand boats on mudflats at low tide and submerge the same ground completely a few hours later. The Bristol Channel, between England and Wales, is the closest genuine rival, with a tidal range that is impressively large by world standards but still smaller than Fundy's. Ungava Bay in northern Canada and Cook Inlet in Alaska both experience strong, well-documented tides driven by similarly funnel-shaped coastlines, which makes them plausible-sounding answers, but neither reaches the extreme range recorded in the Bay of Fundy.

Source: Fundy Biosphere Region / Government of Nova Scotia tidal records, summarized by the Guinness Book of World Records (1975) recognition of Burntcoat Head, Nova Scotia

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Indonesia is the world's largest archipelago nation, its territory spanning more than 5,000 kilometers from east to west, roughly the width of the continental United States, and made up of tens of thousands of islands, a count that varies between official surveys depending on how small or unnamed islands are registered, but which consistently dwarfs every rival nation in total extent. The Philippines is itself a major archipelago, with thousands of islands of its own, which makes it a genuinely tempting choice, but its combined land area and east-to-west span are much smaller than Indonesia's. Japan consists of thousands of islands too and is often pictured as a classic island nation, yet its main chain stretches a far shorter distance and its total island count, while large, does not match Indonesia's scale. The Maldives is a striking example of a nation built almost entirely from small coral islands and atolls, but it is also one of the smallest countries on Earth by land area, nowhere near archipelago-nation scale.

Source: CIA World Factbook: 'Indonesia' (cia.gov/the-world-factbook/countries/indonesia)

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Point Nemo, at 48 degrees 52.6 minutes south and 123 degrees 23.6 minutes west, is the oceanic pole of inaccessibility, the single point in any ocean that is farthest from land; its nearest shores, Ducie Island, Motu Nui near Easter Island, and Maher Island in Antarctica, are each roughly 2,688 kilometers away. The payoff is genuinely strange: because the International Space Station orbits at an altitude of around 400 kilometers, astronauts passing overhead are sometimes physically closer to Point Nemo than any human on Earth's surface, which is part of why space agencies use the surrounding waters as a deliberate crash zone for decommissioned spacecraft. The Mariana Trench is a tempting answer because it holds the ocean's deepest point, the Challenger Deep, but that record is about depth, not distance from land, and the trench sits near a chain of islands. The Sargasso Sea is a famous mid-Atlantic region defined by calm currents and floating seaweed, not by remoteness from shore. The Tonga Trench is the second-deepest trench on Earth, another depth record unrelated to this measurement.

Source: Encyclopaedia Britannica: 'oceanic pole of inaccessibility' (britannica.com/place/oceanic-pole-of-inaccessibility)

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Vostok Station, a Russian research base sitting about 3,488 meters above sea level deep in the interior of the East Antarctic ice sheet, recorded a surface air temperature of -89.2 degrees Celsius on 21 July 1983, the coldest instrument reading ever taken at ground level on Earth; its combination of high elevation and extreme distance from any ocean's moderating warmth is what lets heat radiate away so completely on clear, still polar nights. Amundsen-Scott South Pole Station sits exactly at the pole itself and sees brutally cold winters, which makes it a reasonable guess, but its lower elevation keeps it slightly warmer on average than Vostok. McMurdo Station is Antarctica's largest base, but its coastal location exposes it to ocean-moderated air, so its temperatures are notably milder than those found deep inland. Concordia Station, at Dome C, is a genuine modern rival for extreme cold and has come close to Vostok's reading in recent decades, but it has not yet surpassed the 1983 record.

Source: National Snow and Ice Data Center: 'New study explains Antarctica's coldest temperatures' (nsidc.org/news-analyses/news-stories/new-study-explains-antarcticas-coldest-temperatures)

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The Great Barrier Reef, off the coast of Queensland, Australia, stretches more than 2,000 kilometers and is built from nearly 3,000 individual reefs and hundreds of islands, making it both the largest coral reef system and, according to NOAA, the largest structure on Earth ever built by living organisms, large enough to be visible from space. The Belize Barrier Reef is the second-largest coral reef system in the world and a genuinely important, biodiverse site, but at under 300 kilometers long it is a small fraction of the Great Barrier Reef's scale. The Red Sea's coral reefs are ancient, resilient, and span a long coastline, which makes them a plausible-sounding rival, but their total reef area falls well short of Australia's reef system. The New Caledonia Barrier Reef is one of the largest reef systems in the Pacific and a UNESCO-listed site in its own right, yet it, too, is considerably smaller than the Great Barrier Reef.

Source: NOAA Ocean Service: 'The Great Barrier Reef is the largest living structure on Earth' (oceanservice.noaa.gov/facts/gbrlargeststructure.html)

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Scoresby Sund, on Greenland's remote eastern coast, is recognized by Guinness World Records as the world's longest fjord system; its longest branch, the Nordvest Fjord arm, extends more than 300 kilometers inland from the open sea, and the whole tree-like network of connected fjords covers an area larger than many countries. Sognefjord, in Norway, is that country's longest and one of the most famous fjords on Earth, reaching roughly 205 kilometers inland, which makes it a strong and genuinely tempting rival, but it is still far shorter than Scoresby Sund's longest arm. Nordfjord is another well-known Norwegian fjord, scenic and substantial in its own right, yet shorter than Sognefjord and so an even greater distance from the record. Milford Sound in New Zealand is world-famous for its dramatic cliffs and is technically a fjord despite its name, but it stretches only about 15 kilometers inland, making it one of the shorter fjords commonly visited by tourists rather than a contender for the length record.

Source: Guinness World Records: 'Longest fjord' (guinnessworldrecords.com/world-records/66647-longest-fjord)