Wall foundation constructed from unworked/ roughly worked stone (tufo anf basalt) and bound with mortar. This may have provided the border between two rooms E of the road. Wall was truncated at a later date by the action of cutting the drainage channel (4002) which diagonally cuts the western end. The eastern end does not look original and was perhaps cut by an unknown action (it probably did not end too much farther because there are no further wall traces visible in the scarp just E of the wall. Outer blocks of foundation larger and roughly faced, with smaller rubble in between. Alignment differs from walls 4007 and 4008 to the S, but perpendicular to E retaining wall of road (2080 equals 4006) and seems to have similar alignment to some walls of the fullonica (2193). This wall represents the lstest building phase in this area.