A World Heritage Site

This classification designates outstanding physical, biological, and geological features;

The Dorset and East Devon Coast provides an almost continuous sequence of Triassic, Jurassic and Cretaceous rock formations spanning the Mesozoic Era, documenting approximately 185 million years of Earth history. It also includes a range of internationally important fossil localities – vertebrate and invertebrate, marine and terrestrial - which have produced well-preserved and diverse evidence of life during Mesozoic times.

The cliff exposures along the Dorset and East Devon coast provide an almost continuous sequence of rock formations spanning the Mesozoic Era, or some 185 million years of the earth's history. The area's important fossil sites and classic coastal geomorphologic features have contributed to the study of earth sciences for over 300 years.

Excert from the World Heritage Convention site
http://whc.unesco.org/nwhc/pages/doc/main.htm