The World Heritage Site extends from the cliff top to the low water mark (except around the Isle of Portland) between Exmouth in east Devon and the southern point of Studland Bay in Dorset. It does not include the developed frontages of the gateway towns.

The World Heritage Site extends from the low water mark to the top of the cliffs but excludes the built up sea frontages of the gateway towns.

Virtually all of the land in the World Heritage Site has legal protection. The Site lies within 14 Sites of Special Scientific Interest (SSSI), which are regulated by Natural England (originally English Nature) the English Government's conservation agency. The Axmouth to Lyme Regis Undercliffs is additionally recognised as a National Nature Reserve. These sites identify and protect both geological and biological interests. The SSSIs encompass 66 Geological Conservation Review (GCR) sites of national and international importance for the earth sciences. These have been identified by the Joint Nature Conservation Committee (JNCC), the UK Government's advisor to nature conservation. The biological interests within the SSSI network include vegetated sea cliffs, a rare habitat recognised and protected in many places by Special Area of Conservation (SAC) status, a European Union Habitat Directive designation. In addition, many of the fields inland from the cliffs are designated as SSSI's for flora and fauna while the Fleet Lagoon and Exe Estuary are European wetland sites protected as RAMSAR sites.

The natural interests of the coast are protected by Sites of Special Scientific Interest (SSSI) designations

Most of the Site also lies within the East Devon Area of Outstanding Natural Beauty (AONB) and the Dorset AONB. These two designated areas are nationally important landscapes, and protect the setting for the Site. The exception is the Isle of Portland which is not an AONB.

The setting for the World Heritage Site is provided by the Dorset and East Devon Area of Outstanding Natural Beauty (AONB) designations. The exception is Portland where quarrying is very much part of the character of the island.

The World Heritage Site is protected by the UK and European conservation laws and the planning process which must take them into account. The World Heritage designation is a material consideration but the protective mechanism is through existing conservation designations; principally the SSSI and AONB designations.

Erosion is the key feature that maintains both geological and biological interests along the coast. Continued erosion maintains the rock outcrops within the cliffs and delivers fossils to the beaches. Erosion itself forms part of the justification for World Heritage Status in that this coast is a ‘living laboratory' for geomorphology as it contains superb examples of landslides, beaches, lagoons, bays and headlands and sea stacks. Much of the biological interest is in the form of plants and animals that colonise this constantly changing environment; plants such as Purple Bromwell, Nottingham Catchfly and Portland Sea Lavender together with bees, wasps and beetles that make their homes in the freshly disturbed soft rocks.

Erosion is the very reason why the coast is so interesting, diverse and beautiful but continued erosion will increasingly threaten land and properties behind the cliffs.

The greatest threat to the Site is through the development of coastal defences and these, naturally, focus on the edges of the gateway towns where existing defences meet the natural coastline.

The construction of coastal defences are the greatest threat to the World Heritage Site.

Find out more about Natural England , the Joint Nature Conservation Committee and Dorset Area of Outstanding Natural Beauty and East Devon Area of Outstanding Natural Beauty .