At first it would appear that two different kinds of stones were used in this wall, separated by the line of vegetation. The stones above this line are rough and the ones below, at lower right of the picture, are smoother. Thick walls like this one, however, were built by placing two rows of stones with their faces outward and filling the space between with rubble and mortar. Only the face of the stones was dressed and never the back, because the back would not have been seen and the rougher surface provides a better grip for the mortar. The rough upper stones, then, are actually the back of the stones that face southward towards the Temple Mount. The vegetation grows in the core of the wall, and below that are the smoother stones that face the pool. The original plaster, which would have been attached to this wall, has not survived.