Circular tufo block 5174 is a column base exposed during the opening of F-North trench for the 2013 season. It is associated with the northern limit of monumental ashlar wall 5159 and monumental staircase 5170, where both meet the upper terrace. It is possible that another column sat at the limit of the other staircase wall (5169), which was almost entirely robbed out.
NS wall along main area F stairs