Island castle set in the middle of Mount's Bay, just off the coast of Marazion. The Mount is now managed by the National Trust but remains the home of St Aubyn family.
The 16th century Old Blockhouse is located at the southern end of Old Grimsby harbour on Tresco. It was built in the reign of Henry VIII as part of a series of coastal defences to protect against invasion from the French.
Clifftop ruins of castle which was allegedly the fortress used by King Arthur.