Dover Castle is one of England's oldest and most famous fortresses. A medieval castle forms its core, but from the 1740s onwards its outer defences were dramatically reshaped in the face of the threat of invasion from France. During the Napoleonic Wars, a network of military tunnels were cut within the famous white cliffs to provide barracks for the garrison. These tunnels were adapted during the Second World War and played a vital role in Britain's war effort: it was from here that the near-miraculous evacuation of British and French troops from Dunkirk ware masterminded in May and June 1940. This new guidebook, packed with plans, maps, historic photos and eyewitness accounts, tells the story of how the castle's defences were adapted to meet the needs of modern warfare right up to the Cold War.