Turret 51A (Piper Sike) (grid reference NY58826530) is of the type normally associated with the Turf Wall, and later replaced in stone.[3] The turret was excavated in 1927 and again in 1970.[3] The entrance was on the east side and a substantial platform against the north wall.[3] Cooking hearths and rubbish were found spread over the rest of the turret.[3] Occupation is not believed to have continued later than the 2nd century AD.[3] The turret was consolidated after 1970 and survives to a maximum height of 0.8 metres.[3]