Remains of castle built for coastal defence on the north side of Tresco
16th-century fort built over St Mary's Pool harbour, but never finished
17th-century round tower positioned on a rocky promontory guarding the anchorage between Bryher and Tresco.
Extensive defensive walls and earthworks dating back to the 16th century
Clifftop ruins of castle which was allegedly the fortress used by King Arthur.
Perfectly preserved coastal fortress built by Henry VIII. In partnership with its twin, Pendennis, it guards the entrance of the Fal Estuary.
Surrounded by a deep moat and perched on a high mound, the huge circular keep of this castle, built at the turn of the 14th century, survives in good condition.
Pendennis Castle was built in the middle of the 16th century by Henry VIII as one of a pair of forts, with St Mawes Castle, to protect the Fal Estuary from the threat of invasion from France and Spain
Castle set on the high motte (mound) of a stronghold built soon after the Norman Conquest
St Catherine's Castle was built, as one of several fortifications running along the south coast in 1536, to protect Fowey harbour from French Invasion and is now managed by English Heritage