It is one of the centres run by Field Studies Council and offers residential and non-residential fieldwork for schools, colleges and universities, holiday accommodation and professional and leisure courses in natural history and arts.

Although there was a proposal for an artillery battery on this site in 1829, the present fort is a result of a recommendation by Sir John Fox Burgoyne, the Inspector-General of Fortifications, in 1850.

In 1902, the fort was sold to Lieutenant-Colonel A. Owen-Evans of the Royal Engineers, who converted it into a home for his family, but it changed hands when he died in 1925.

During the Second World War, the fort was requisitioned by the Admiralty for use as a degaussing and mine-watching station, but was returned to the owner at the end of hostilities.

The landward (western) side of the fort facing the ditch consists of a loopholed wall, in the centre of which is a D-shaped bastion with embrasures for three guns.