Old Harry Rocks in Dorset stand at the tip of a chalk headland between the bays of Studland and Swanage. Chalk is made up of the fossilised remains of single-celled organisms which lived in the sea. Over thousands of years, millions of fossils became compressed to form the rock. As sea levels fell, the chalk became exposed. Old Harry Rocks form a headland as the chalk is more resistant to erosion than the surrounding clays. With thanks to the British Geological Survey. Ordnance Survey mapping © Crown Copyright.

Can be used during a module on coastal processes. Students could be asked to explain how the landforms at Old Harry were created. They should note down the names of any rock types and describe how the rock formed and what the rock looks like. Finally, students should explain several reasons why Old Harry is eroding more slowly than the land around it.