The biggest draw at Dover Castle is the secret wartime tunnels. The claustrophobic chalk-hewn passageways were excavated during the Napoleonic Wars and then expanded to house a command post and hospital in WWII. The highly enjoyable 50-minute guided tour (every 20 minutes, included in the ticket price) tells the story of one of Britain’s most famous wartime operations, code-named Dynamo, which was directed from here in 1940 and saw hundreds of thousands of men evacuated from the beaches at Dunkirk.
The story is told in a very effective way, with video projected sharply onto the tunnel walls and sounds rumbling through the rock. At one point the entire passageway is consumed in flames and at others visitors are plunged into complete darkness.