Mighty Dover Castle commands a view of the shortest sea crossing between Britain and continental Europe, a position of immense strategic importance. But within the walls of the medieval castle stands a much older building, dating from a time when Britain was an outpost of the Roman Empire.Around 2,000 years ago, in the early 2nd century AD, the Romans built a pharos, or lighthouse, here. This would have guided the ships of a Roman fleet into the harbour below.Not only is the Dover pharos the most complete standing Roman building in England, it's also one of only three lighthouses to...