aerial photograph of the white cliffs of Dover with Dover Castle behind. Most of the castle dates from the 13th Century and was built under the reign of King Henry II, however the site had been occupied since the iron age and was in use during the Roman occupation. The Romans built the light house which has survived into modern times by being used as the bell tower for the adjacent Saxon St Mary in Castro Church.The Castle was extensively modified during the Napoleonic Wars including the construction of underground barracks, the only one of its type in Britain.These underground structures were then extended and re used as a command and air raid shelter during WW2. Today the castle is run by English Heritage and is open to the public.