Chalk laid down flat on a seabed does not arrive 128 metres in the air on its own. During the ice ages of the last hundred thousand years, glaciers bore down on this corner of the Baltic and shoved the chalk beds up off the seafloor, compressing them, buckling them, driving them into folds. The evidence is written across the cliff face for anyone who looks: the layers are not level. They rear, tilt, pinch out and double back on themselves, streaked with dark bands of glacial debris caught in between like filling in a pastry. The same pressure raised the country behind the cliff into a run of steep hills. Aborrebjerg, a couple of kilometres inland, reaches 142 metres and is among the highest ground in Denmark — which tells you as much about Denmark as it does about the hill.

Chalk is soft, water gets into it, and Møns Klint sheds itself in slabs. On 27 January 2007 the projecting mass of Store Taler collapsed, throwing down enough rock to build a raw peninsula roughly 300 metres long at the foot of the cliff — a new headland made in an afternoon, and one that the sea has been dismantling ever since. Sommerspiret, the Summer Spire, was the most painted feature on the coast: Christoffer Wilhelm Eckersberg put it on canvas in 1809, Frederik Hansen Sødring in 1830. It fell into the sea in 1998. Nothing here is permanent, not even the landmarks the Golden Age painters treated as monuments. A landslide in 1905 took the wooden cross that stood at the cliff edge above Liselund, along with the little park's chapel and bathhouse.

The narrow shingle at the base is where the cliff hands over its contents. Every collapse and every winter storm turns out fossils — the fossilised guards of squid-like cephalopods, the spines of sea urchins, oysters and a range of shellfish, all of them contemporaries of the algae that make up the rock around them. You do not need a hammer or a permit; you need to look down and be patient, and to keep an eye on what is happening above you. Loose chalk and flint come off the face without warning, and the beach directly beneath an overhang is not a place to linger. Access is by staircase from the woods on top, in several places along the six-kilometre stretch, and the climb back up is the part nobody warns you about.

Chalk changes what will grow. Beech forest runs right to the cliff edge here, and the lime in the soil gives the leaves a distinctive pale green that they hold through the whole summer instead of darkening in July like beeches elsewhere. Walk down the staircases and you pass tall lady orchid, Orchis purpurea, growing in the chalk under the steps, one of several orchids that thrive on ground too alkaline for most competition. The extremely rare large blue butterfly, Maculinea arion, is found in the area. Peregrine falcons breed on the cliff face — the fastest animal alive, capable of 350 kilometres an hour in a stoop, and entirely at home on a vertical white wall with no predators on it. BirdLife International has designated the area an Important Bird Area.

On 29 May 2007, close to the cliff tops, Queen Margrethe opened the GeoCenter Møns Klint. PLH Architects won an international competition for the design, and the building's job is to explain what visitors are standing on: how the chalk formed, how the ice reworked it, and what comes out of the fossil beds below. Around 250,000 people a year now come to the cliffs. Marked paths for walkers, riders and cyclists run through the woods and hills behind, past ponds and marshes, and the clifftop path connects the staircases down to the shore. On 13 July 2025, Møns Klint was accepted for inscription on UNESCO's World Heritage List. It is an odd thing to protect — a landform whose defining behaviour is to fall apart — but that is rather the point. The cliff is not a monument. It is a process that happens to be visible.