Mount Thor on Baffin Island holds the record for the greatest purely vertical drop on Earth — roughly 1,250 metres of overhanging granite. For sheer total height, Great Trango Tower in Pakistan presents a face of about 1,340 metres, while Norway's Kjerag and Hawaii's Kalaupapa sea cliffs top the lists for coastal drops at around 1,000 and 900 metres respectively.
The record depends entirely on which question you ask
There is no single tallest cliff, because "tallest" hides at least four different measurements, and lists that mix them produce contradictory rankings.
- Greatest vertical drop — the longest continuous fall where a dropped stone touches nothing. Mount Thor wins this outright because its face actually overhangs.
- Greatest face height — base to summit measured along the wall, which permits ledges and lower-angle sections. Great Trango Tower and several Baffin Island walls lead here.
- Greatest sea cliff — measured from the waterline. Kalaupapa on Molokai and the cliffs of northeast Molokai are the usual claimants.
- Greatest relief — total elevation change from valley floor to summit, which includes slopes that are not cliff at all. Rakaposhi and Nanga Parbat in Pakistan dominate, but these are mountainsides rather than cliffs.
Almost every argument about cliff records dissolves once you specify which of these four you mean.
Mount Thor and the overhanging record
Mount Thor sits in Auyuittuq National Park on Baffin Island, in the Canadian territory of Nunavut. Its west face descends about 1,250 metres at an average angle of roughly 105 degrees — past vertical. That overhang is the whole story: a plumb line dropped from the top hangs free the entire way and lands well out from the base.
The rock is granite, and the geometry is a product of glaciation. Ice moving through the valley undercut the wall, removed the debris that would otherwise have piled up as a supporting apron, and left the face unsupported. Granite is strong enough in compression to stand in that configuration; almost no sedimentary rock would be.
The mountain is genuinely remote. There is no road, and reaching the base means a boat trip up Pangnirtung Fiord followed by a long walk up the Weasel River valley. Its isolation is part of why it went unclimbed until 1985.
The great sea cliffs
Coastal cliffs are attacked from below in a way inland walls are not. Waves undercut the base, the overhang eventually fails, and the cliff retreats landward while staying steep. That process caps how tall sea cliffs can grow, which is why the tallest are around 1,000 metres rather than 1,500.
Hawaii
The north coast of Molokai carries sea cliffs commonly cited between 900 and 1,010 metres. They exist because a catastrophic collapse removed the northern half of the volcano, leaving the exposed interior as a wall. Similar giant landslide scars shape much of the Hawaiian island chain.
Norway
Kjerag drops roughly 1,000 metres to Lysefjorden, and the nearby Preikestolen offers a flat platform about 600 metres above the same water. Both are glacial rather than marine in origin — the fjord was carved by ice and later flooded, so the "sea cliff" is really a valley wall that happens to end in salt water. The geography of fjords explains why Norway has so many of these.
The North Atlantic
Ireland's Slieve League and Croaghaun on Achill Island both exceed 600 metres. The Faroe Islands and the sea stacks of St Kilda in Scotland carry cliffs in the same range, and Cape Enniberg in the Faroes approaches 750 metres. The better-known Cliffs of Moher are modest by comparison at about 214 metres — their fame rests on continuity and accessibility rather than height.
The Southern Ocean
Tasmania's Cape Pillar and the dolerite columns of the Tasman Peninsula reach around 300 metres, and are notable less for height than for form: the rock cooled into vertical hexagonal columns, producing faces that are geometrically sheer rather than merely steep. On the sub-Antarctic islands and along parts of the Chilean and South Georgian coasts, glacial troughs meeting open ocean produce comparable walls that are almost never visited and correspondingly poorly surveyed.
Big walls: the climbers' hierarchy
Climbers rank cliffs by a different standard again, weighing sustained steepness and continuous difficulty over raw metres.
Great Trango Tower in the Karakoram presents the largest near-vertical face at roughly 1,340 metres. Baffin Island's Mount Asgard and the walls of Sam Ford Fiord offer 1,000-metre-plus granite in a similar Arctic setting to Mount Thor. Yosemite's El Capitan, at about 900 metres, is shorter than all of them but is the most climbed big wall on Earth because it is granite of exceptional quality with a road at its base.
The Trolltind wall in Norway, at roughly 1,100 metres, was long treated as Europe's tallest vertical rock face, and the Eiger's north face in Switzerland reaches about 1,800 metres of relief — though it is a mixed rock-and-ice face rather than a clean wall, which is precisely why it earned its reputation.
Sea cliffs and inland walls are made by opposite processes
The most useful comparison in this whole subject is between the two families, because they look alike and form in nearly opposite ways.
A sea cliff is maintained by erosion. Waves remove material at the base, the face collapses, and the cliff steps backward. The cliff is a retreating boundary, and the rock exposed today was inland rock a century ago. The White Cliffs of Dover retreat measurably within a human lifetime.
An inland glacial wall is abandoned by erosion. The glacier that cut it has gone. Nothing is actively removing material from the base, so the face simply stands, slowly weathering, for as long as the rock holds. Mount Thor's overhang survives only because nothing is undercutting it any more.
The practical consequences differ sharply:
- Rate of change — sea cliffs retreat centimetres to metres per year; glacial walls change imperceptibly
- Rock type — sea cliffs form in almost anything, including chalk and volcanic ash; the tallest vertical walls require strong crystalline rock
- Debris — waves clear the base of a sea cliff continuously; a glacial wall accumulates a talus cone that gradually buries its own lower section
- Maximum height — undercutting caps sea cliffs near a kilometre; unsupported granite walls can exceed that
The ecology of a vertical world
Tall cliffs are not empty rock. They are one of the few habitats on Earth defined primarily by inaccessibility, and that single property drives everything that lives there.
Seabird colonies are the clearest case. Guillemots, kittiwakes, razorbills, fulmars and gannets nest on North Atlantic ledges precisely because ground predators cannot reach them — St Kilda and the Faroese cliffs support colonies numbering in the hundreds of thousands. Guillemots lay a distinctively pear-shaped egg that rolls in a tight arc rather than off the ledge, an adaptation that only makes sense on a bare vertical surface.
Cliff faces also act as refuges for plants. Botanists repeatedly find relict species surviving on ledges that grazing animals cannot reach, sometimes hundreds of kilometres from the nearest other population. Some of the oldest known trees in eastern North America are stunted eastern white cedars clinging to the Niagara Escarpment, kept small by exposure and poor soil but living for well over a thousand years because nothing disturbs them.
Raptors complete the picture. Peregrine falcons, golden eagles and various vultures all favour cliff eyries for the same reason the seabirds do, with the added benefit that a high ledge gives immediate access to rising air.
Why the numbers keep changing
Published cliff heights vary more than almost any other geographic statistic, and there are concrete reasons rather than mere sloppiness.
Defining the base is the central problem. On an inland wall, does measurement start at the top of the talus slope or at the buried bedrock beneath it? Those points can differ by 200 metres. On a sea cliff, does it start at high water, low water, or the seabed? A cliff at Molokai measured from the seabed would gain hundreds of metres instantly.
Defining the top is nearly as awkward. A wall that leans back into a broken slope has no obvious summit line, and different surveyors pick different points.
Method matters too. Older figures came from barometric altimeters and rope lengths; modern ones come from satellite elevation models and lidar, which are far more precise but still struggle with overhangs, since a downward-looking sensor cannot see beneath a lip. Where a face overhangs, the mapped surface is genuinely ambiguous.
Where sources disagree, the useful habit is to treat the figure as approximate and to check which of the four measurements it belongs to. If you enjoy this kind of superlative geography, our guide to the world's largest plateaus runs into the same definitional problems from the opposite direction, and the explainer on how cliffs form covers the underlying mechanics in more detail.