St Catherine's Fort is set upon St Catherine's Island (NPRN 579), an offshore rock bordering south beach in Tenby. It dates from 1868-71, and the remains of St Catherine's Chapel (NPRN 418975) were reportedly demolished during its construction.

One of a chain of Palmerstonian forts built to protect the Admiralty's ship-building yards at Pembroke Dock, this imposing structure cost £50,000 to build and was manned by 100 men and officers. Today it stands derelict.

RCAHMW, 4 August 2010.