St Mawes Castle, Cornwall

St Mawes is the sister castle to Pendennis and protects Falmouth Harbour.

It was built between 1539 and 1545 as part of Henry VIII's defences against French Invasion. It is one of a whole series of forts along the South and Channel Coasts.

The design was leading edge in the mid 16th Century with circular bastions build round a central tower. However it was a design, which soon became obsolete as cannons became more effective.

Nevertheless they were refortified at several later dates when invasion was feared: including the Armada, Napoleonic Wars, the French Invasion, the 1860s and the First and Second World Wars.

During the late 19th Century the naval base in the Fal was protected by a undersea mines which would be set off from the Castkes, when hostile vessels entered the estuary, by an electrical charge. These defences were manned by a unit of Engineer Volunteers raised from Cornish tin miners.