Geograph - photograph every grid square

Stair hole has been formed by erosional processes. The waves have punched a hole through the resistant Portland Limestone exposing the weaker Wealden Clay, Gault Clay and Greensand. These are much less resistant and have been eroded forming an embayment.

Natural Arches are features of coastal erosion. They are found on cliffed coastlines and result from wave attack punching a hole through a headland. They are temporary features in the landscape, their roofs often collapse leaving stacks.

Blowholes are a feature of coastal erosion. They are formed when the roof of a cave collapses leaving a roughly circular hole in the cliff top above. When waves hit the back of the cave spray is sometimes ejected, hence the name.