Mons Klint, English: the Cliffs of Mon, is a striking landmark and tourist attraction along the eastern coast of the Danish island of Mon in the Baltic Sea. The bright chalk cliffs stretch some 6 km from the park of Liselund in the north to the lighthouse in the south. Some of the cliffs fall a sheer 120 m to the sea below. The area around Mons Klint consists of woodlands, pastures, ponds and steep hills, including Aborrebjerg which, with a height of 143 m, is one of the highest points in Denmark. The cliffs and adjacent park are now protected as a nature reserve. Mons Klint is popular with tourists from across Europe with some 250,000 visitors a year. There are clearly marked paths for walkers, riders and cyclists. The path along the cliff tops provides impressive views and leads to steps down to the shore in several locations.
The chalk forming the cliffs consists of the remains of shells from millions of microscopic creatures (coccolithophores) which lived on the seabed over 70 million years ago. As a result of huge pressure from glaciers moving west, the terrain was compacted and pushed upwards, forming a number of hills and folds. When the ice melted at the end of the last ice age about 11,000 years ago, the cliffs emerged. They form part of the same deposits as the cliffs of Rugen, Germany, on the other side of the Baltic. Today, it is possible to find fossils of various types of shellfish as the sea continues to erode the chalk. Erosion also caused one of the highest points on the cliffs, the "Sommerspiret", to fall into the sea in 1998, and in January 2007, there was an even larger landslide around the Store Taler, in the northern part of the cliffs, creating a 300-m long peninsula of chalk and fallen trees stretching out into the sea below.