St Catherine’s Castle is a small fort commissioned by Henry VIII. It is a two-storey building built to protect Fowey Harbour in Cornwall, United Kingdom. A twin battery of 64-pdr RMLS was added on a lower terrace in 1855. One emplacement was modified in WWII to mount a 4.7" naval gun inside a concrete shelter, but was later removed to restore the Victorian gun races.
During 1999 there was some controversy regarding this site and others under the care of the English Heritage organization. Members of a pressure group, the Revived Cornish Stannary Parliament, confiscated several signs bearing the English Heritage name.