An unusual worked stone that we have been referring to as the ‘doughnut’ has been a familiar feature in the southern part of Trench 3 for the last few seasons at Bamburgh Castle. It was first revealed in 2011, but it took two further seasons to lower the ground surface around it sufficiently for its unusual form to become apparent.
It lay immediately west of the metalworking building and is broadly contemporary with that structure, which would make it middle 9th century AD in date. The wear pattern on the side suggests that the top third of the stone was uncovered above the surface for sufficient time for it to wear and erode more than the base which appears to have been set into the ground. We believe therefore that it was inserted into a cut which we have struggled to see. The presence of a small number of what are likely packing stones reinforces this interpretation.
The stone is difficult to interpret and has been suggested as a socket for a timber pivot, a socket for a standing cross, which would be exciting but sadly is rather unlikely give its circular shape. It could also to have been set as a soakaway, given that it is perforated all the way through. Now we have lifted it and examined it seems likely that it started life as a mortar as the upper part of the perforation is smooth and the lower crudely cut through. Our best guess is that it was a large mortar re-used as a pivot stone.