St Catherine’s Castle is located on a high, rocky headland known as St Catherine’s Point, overlooking the entrance to the River Fowey estuary. Originally built in the 1530s, it formed part of King Henry VIII's network of fortifications along the south coast of England.

As is typical of such structures, the castle also played a part in later conflicts such as the English Civil War, the Napoleonic Wars, the Crimean War, when it was fitted out with two new artillery positions, and the Second World War.