The SU is two stones beneath wall 2256, possibly associated with similar blocks (2455) that are north of these stones, and also under the wall. The stones also abut the large ashlar block 2436, possibly serving as leveling stones as the eastern extent of 2436 does not continue under the entirety of 2256. These stones were not fully exposed as of the end of the 2015 season. During post-excavation study, this feature was reinterpreted as likely leveling surfaces for wall foundation 2256.
The SU is composed of stones related to an earlier phase of the wall.
S. tufo blocks beneath wall 2256, E. of 2436