But the real surprise was the left hand side which revealed painted wall plaster, probably still attached to the remains of a wall. In the picture, the two loose tesserae (mosaic tiles) are sitting on the top of the wall, which must have been cut down to floor level. The edge of the wall runs from the bottom left to the top right and shows painted wall plaster in the middle. This is quite complicated but it suggests that the room had a much lower earlier floor which was raised to the present level. At the same time, the wall was moved slightly to the left, keeping the remains of the old wall in place.