Turret 8B (Union Hall) was investigated in 1929 and positioned 532 yards (486 m) west which places it 548 yards (501 m) east of Milecastle 9, although sources of the period disagree on this point.[6] When it was excavated the road of the time ran alongside the turret, and the south wall, 19 feet 10 inches (6.05 m) long with a doorway set in it, was found to be two courses of stone high. The road was later realigned and now lies over the site, leaving no visible surface trace of the turret.[6]
Ordnance Survey location: 54.989291°N 1.714684°W