The southern entrance (also known as Archcliffe Gate) to the western heights fortress was constructed in the 1860’s as part of a major revision of the southern defences. It was located at a point where the South Military Road attained the crest of the ridge. One of the major features of this entrance was the South entrance ditch which barred access to the ridge top, this was cut down the steep hill from the South Parapet to the edge of the cliff overlooking the harbour. The whole South entrance was demolished in 1967 and the ditch infilled. (location accurate to the nearest 5m based on available information)