The coast is made up of a complex sequence of rocks, which have been jumbled up by geological folds and faults.

At Lulworth Cove, limestone forms a massive bastion against the sea. A perfect horseshoe bay has developed where a stream breached the limestone allowing the sea to enter the valley and hollow out the softer clays lying behind the limestone barrier

Towards the end of the Jurassic period, about 144 million years ago, sea levels dropped and a series of islands emerged in Purbeck, surrounded by saline lagoons and channels.

The rocks at Kimmeridge Bay were once the floor of a deep, tropical sea rich in pre-historic life.

The sheer cliffs of the south Purbeck coast offer spectacular coastal walking.  Formed of Portland Stone and Purbeck Limestone, the rocks can be seen in the old cliff quarry workings of Seacombe, Winspit and Dancing Ledge.