Often described as 'The Key to England', Dover Castle is the largest castle in England and dates from 11th century, though there was probably an Iron Age fort on the site and the complex includes a Roman lighthouse and Saxon church. The fortress was garrisoned until 1958 and offers a unique insight into Britain's history. A medieval court has been recreated inside the Great Tower. Underneath the castle, deep inside the famous White Cliff, are tunnels which date from medieval times. During WW2, these were the HQ for the control of Operation Dynamo, the evacuation of Dunkirk, and there are vivid displays illustrating this. There is an underground hospital to visit too, and a WW1 signal station. Dover Castle has appeared in several film/TV productions, including 'The Other Boleyn Girl' and 'Wolf Hall'.