Dubris or Portus Dubris was a town in Roman Britain (it is now Dover, Kent, England). As the closest point to continental Europe and the site of the estuary of the Dour, the site chosen for Dover was ideal for a cross-channel port. In the Roman era, it grew into an important military, mercantile, and cross-channel harbor. It was fortified and garrisoned initially by the Classis Britannica, and later by troops based in a Saxon Shore Fort.

Two lighthouses, each called the Pharos, were built soon after the conquest. They were sited on the two heights (Eastern Heights and Western Heights) and modeled on the one built for Caligula's aborted invasion at Boulogne.

The lighthouse on the Eastern Heights still stands in the grounds of Dover Castle to 80 feet high (close to its original height). What little remains of the western lighthouse is called the ‘Bredenstone’ or the ‘Devil's Drop of Mortar’ after the nearby lost village of Braddon.