Dover Castle is a medieval castle in Dover, Kent. It was founded in the 11th century and has been described as the "Key to England" due to its defensive significance throughout history.It is the largest castle in England. Dover Castle commands the Strait of Dover, the shortest sea crossing between England and continental Europe, a position of strategic importance throughout history.
Castle Hill was shaped into massive defences capped by medieval walls and towers and later, from the mid 18th century, by the earthworks of a garrisoned infantry and artillery fortress. Beneath the surface, cut into the chalk of the North Downs, are networks of tunnels to enable the garrison to move, plan and live in safety.
King Henry II began to build the present castle in the 1180s, and over the next 800 years its buildings, defences and tunnels were adapted to meet the changing demands of warfare, right into the era of nuclear weapons.
