I live near Dover (Dubris), and we've still got a Roman lighthouse sitting on top of the eastern cliff. It used to have a neighbour on the western cliff but that fell down a few hundred years ago. Rowing galleys over from France at night, the crew would simply aim between the two lighthouses, which burned wood, and arrive at the harbour.
We also have the remains of a fine Roman house in the town with painted plaster walls and a mosaic floor. Amazing to thing that the Roman fleet was based here and defended the British coastline for around 300 yrs. The Goodwin Sands just off our coast were the graveyard of many Roman galleys with urns, coins etc. still being discovered there when the tide is out.