The coast around Lyme Regis is unstable and subject to landslips. Jurassic age fossils are regularly exposed by these landslips and can be found on the beaches below the cliffs after the sea has washed away the mud of the landslip.

The imposing grey cliffs on the coast line around Lyme Regis are mainly composed of Blue Lias consisting of thin alternating shale’s, marls and limestone’s. These were the first normal marine sediments resulting from the flooding in of the sea over the deserts and lagoons of the Triassic period.

As the sea opened and deepened, marine creatures increased in numbers and variety. Ammonites, Ichthyosaurs and Plesiosaurs developed living in the shallow warm water above the muddy sea-floor. These conditions provided a continual supply of dead organisms which fell onto the sea bed, where many became fossilised when the sea bed sediments hardened with age.

Mary Anning an early 19th-century fossil collector, dealer and palaeontologist was born in Lyme Regis.

Due to her skill in locating and preparing fossils, as well as the richness of the Jurassic era marine fossil beds at Lyme Regis, she made a number of important finds.

These included the first ichthyosaur skeleton to be correctly identified, the first two plesiosaur skeletons ever found, the first pterosaur skeleton located outside Germany, and some important fish fossils.

Her work was an important part of fundamental and far reaching changes that occurred during the early 19th century in scientific ideas about prehistoric life and the history of the earth.