This appears to be the fill of a foundation trench for wall 5439. We determined the bottom of the fill based on the fact that the inclusions began to continue under the walls on the south and east sides. However, it was at first surprising that we did not find bedrock at the bottom of the fill, but instead there was more soil. Thus, it is strange that the abutting walls of the fill appear to be sitting on at least several more inches of soil (probably natural, pre-anthropic layers, as revealed elsewhere in this area), and the stone revealed by the removal of the fill under the first course of stones is cut, but currently this lower single stone has an unknown function. It is possibly a kind of stabilizing header for the foundation. The fill is interrupted half way through the room by the earlier excavation by the Soprentendenza who left a large poured concrete slab in the middle of the room. It seems likely that if this is a fill of a foundation trench, it would have continued rest of the length of the wall, but if it did, it is now lost due to the earlier excavation of the area Sopraintendenza.