St Catherine’s Castle

St Catherine's Castle is a small Device 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-pounder rifled muzzle-loading guns was added on a lower terrace in the 19th century. 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.

St Catherine’s Castle is a small harbour defence castle, built as part of Henry VIII's south coast fortifications in the late 1530s. A map of Fowey Harbour of 1540 describes it as "half-made". It receives its name from the rocky headland it sits on known as St Catherine's Point. The building work was supervised by local man Thomas Treffry, who went on to supervise the building of Pendennis and St Mawes castles in the 1540s. It was kept in repair throughout the Tudor period and manned by the Royalists during the first part of the English Civil War (1642–6), but by 1684 it was described as "ruinous".

In 1786 the blockhouse held six cannons but it was abandoned, after the Napoleonic Wars, in 1815. It was refurbished in 1855 to form a gun battery just below the blockhouse, and in 1887 this was armed with two 64-pounder rifled muzzle-loading guns. By the end of the 19th century it was again abandoned.

In June 1940 a gun battery and observation post stretching from the castle itself to the higher ground to the west was constructed, and two 4.7-inch naval guns were installed. By October 1942 a French 75mm gun had also been installed at the site. Most of the 1940s concrete defences were dismantled after the war. The site is now in the care of English Heritage.