"... the Clyde and the Forth, which are carried far inland by the tidal waters of opposite seas, are separated by but a narrow distance: this space was fortified during this [fourth] summer by Roman garrisons ..." (Tacitus Agricola XXIII.i)
The small fort at Mollins was discovered from the air in 1977 and examined on the ground in 1978, when it was assigned a foundation date sometime in the late-first century. It covers an area of only 1 acre (0.4ha) and lies some 3 miles (4.5 km) south of the later Antonine Wall fort at Bar Hill. It was probably built during the fourth campaign season of governor Gnaeus Julius Agricola c.80/81AD. The forts at Barochan overlooking the Clyde to the west, and at Elginhaugh on the river Esk to the east, are probably contemporary.