Appears to be a drain, with a later robbery cut around it, which likely removed a basin since there is a clear end to the drain in the center of the room. Drain has a clear western shoulder with a repurposed tile and a flat basalt. Drain cover in concrete appears to be intact or slightly collapsed in the north, continuing under 7185 to connect with drain in room 4, SU 7196. The bottom of the drain is clear, but seems to continue, in the form of a white mortar surface to the SW (SU 7231).