It was founded in 1961 and is one of 46 wildlife trusts across the UK and the Isle of Man and Alderney.

[a] Nineteen are Sites of Special Scientific Interest, one is a national nature reserve, eleven are local nature reserves, eight are Special Areas of Conservation, three are Special Protection Areas, three are Ramsar sites and seven are Nature Conservation Review sites.

Its headquarters at Woods Mill, south of Henfield, is also a nature reserve with a lake, woodland and meadows.

This area is chalk and to the north is the Weald, which is composed of heavy clays and sand.

The coast has a succession of holiday towns such as Brighton, Eastbourne, Bognor Regis and Worthing.