The cliffs on this part of the coast are being eroded as sections crumble away and landslides occur. These processes reveal successive layers of sedimentary rock, uncovering the geological history at the modern coastline over a period of 185 million years, and disclosing an almost continuous sequence of rock formations covering the Triassic, Jurassic and Cretaceous periods. The fossils found in the area and the coastal geomorphologic features of this dynamic coast, have advanced the study of earth sciences for more than two hundred years. The area covered by the designation comprises the land between the mean low water mark and the top of the cliffs or the back of the beach.