There were about a dozen stone huts built into the walls of the enclosure so that the central space was open.

[3] The wall was constructed from orthostats – standing stone slabs – which enclosed rubble.

A parapet would have made the wall's height about thirteen feet in total – comparable with a standard Roman vallum.

The construction of the walls and huts is not Roman in pattern and R. G. Collingwood suggested that this was an example of the castella Brigantum (forts of the Brigantes), which appear in the work of Juvenal.

[1] N. J. Higham; G. D. B. Jones (1975), "Frontier, Forts and Farmers : Cumbrian Aerial Survey 1974–5", Archaeological Journal, 132 (1): 16–53, doi:10.1080/00665983.1975.11077578