The distinctive cliffs surrounding Southerndown are 180-290 million years old, and are packed with fossils such as the Devil's Toenail - an old version of today's oyster.
The layers are made up of liassic limestone, sandwiched by shale, a brittle substance much like modern earth. It is this substance that makes the cliffs unstable and dangerous. Climbers are advised to head further West towards Ogmore-by-Sea where the cliffs are more solid.
For further information, contact the Glamorgan Heritage Coast Centre on 01656 880157.
