St Mawes Castle and its larger sister castle, Pendennis, were built as part of a defensive chain of fortresses by Henry VIII to protect the south coast of Cornwall, England, United Kingdom. This chain of coastal fortifications are known as Henrician Castles or Device Forts.
St Mawes Castle was built between 1539 and 1545, half way down the hillside on the eastern shore of the River Fal estuary to provide protection to the large inland expanse of water known as the Carrick Roads, near Falmouth (which is the third largest natural harbour in the world). St Mawes was constructed with a central tower overlooking three huge circular bastions attached on the sides in a clover leaf pattern, providing a wide area for gun placements, with gun ports covering every angle of approach to the estuary.
