On top of the Drop Redoubt are the remains of a Roman pharos, or lighthouse, which complemented the Eastern Pharos that still stands in the grounds of Dover Castle, next to the Saxon church of St. Mary in Castro. Both date from the 2nd Century AD, and would have been similar in design lighting the cliffs either side of the Roman Port of Dubris. Remains of the western pharos were lost during the first period of construction of the Redoubt, but the foundations were rediscovered in 1861 during the building of the Officers Quarters. A remainder of the original foundations can still be seen as a horizontal band of Roman rubble and mortar in the inner wall, in the Officers Quarters, immediately below the Bredenstone.
Local names for the remains are the ‘Bredenstone’ or the ‘Devil’s Drop of Mortar’ and at one time the Lord Wardens of the Cinque Ports had their installation ceremony here.
An illustration from "The Illustrated London News" of the Marquis of Dufferin and Ava being installed as Lord Warden of the Cinque Ports at the Bredenstone in 1892.