Procolitia is a settlement and auxiliary fort located close to Hadrian's Wall, near mile castle 30. It is also known as Brocolitia and Carrawburgh.
Only the forts earthworks are visible, built across the vellum which which post dates. Hadrians Wall and the northern ramparts were demolished when General Wade built his early 18th century military road, now the B6318.
The only excavation of the fort was carried out by John Clayton in the 1870's. He revealed a bath-house outside the west gate and the forts south-west corner tower.
The Temple of Mithras is located close to the auxiliary fort Procolitia.
On Procolitia's south-west corner, in the low lying marshy ground three temples were found, all connected to a small tributary stream, known as Meggies's Dene Burn. The one closest to the fort was a 3rd century Mithraeum, discovered in 1949 and its remains can still be seen.