An inscription on the altar is one of the few dedications to a mother goddess found in Roman Britain, and was made by members of the First Cohort of Varduli from northern Spain.

[3] The milecastle lies 150 metres (160 yd) east of the hamlet of Matfen Piers on a section of the narrow wall and, though part of it lies beneath the modern Military Road, is visible as a substantial rise in the hedgerow and as a 0.15m high platform in a cereal field to the south of the road.

[1] The altar discovered, in a 2nd-century AD context, in the 1930s led Birley to suggest that there was a shrine located nearby or that the milecastle had later been converted to religious use.

[8] The First Cohort of Varduli are also mentioned in inscriptions at the Antonine Wall, Longovicium in Durham, Bremenium and Corstopitum in Northumberland and on the Dere Street in Cappuck in the Scottish Borders.

[5] The inscription has led to debate amongst archaeologists as to whether Hadrian's Wall was manned by Roman legionaries or men of the non-citizen auxilia or numeri.

[5] The altar itself is recorded as a separate monument to the milecastle by English Heritage and is now in the collection of the Durham University Museum of Archaeology.

[5] The door was proven to lie at the western end of the south wall and a small and uninscribed altar was discovered beneath a floor of flagstones.

[5][14] The altar showed reliefs of a jug, cleaver, knife and phallus and was located below the last surviving floor level.