Photo Charles Taylor

Also known as Caesar's Camp, the massive earth banks and ditches are the remains of a Norman motte and ringwork castle built in 1140. It is sited on the high Castle Hill which overlooks the Channel Tunnel terminus and which may have been the site of an Iron Age fort. Open all year.

A second castle was built in the 11th century near the harbour but this has since fallen into the sea as the cliffs have eroded.