Small populations of Exmoor pony and Shetland cattle help to maintain the area.[64] Bournemouth is directly north of Old Harry Rocks, the easternmost end of the Jurassic Coast, 96 miles (155 km) of coastline designated a World Heritage Site in 2001.[65] Bournemouth's own coastline stretches from Sandbanks to Christchurch Harbour and comprises mainly sandy beaches backed by gravel and sandy clay cliffs.