This drain cuts through the edge of the so-called granary. If the entire drain were constructed along with the Great Bath, this feature would indicate that the original "granary" was built before the great bath.
The floor slopes down to the southwest corner where a small outlet (top right) leads to a brick drain, which takes the water to the edge of the mound.
At the southwestern corner of the sloping floor, a small drain first passes through the massive walls of the tank and connects to a corbelled arch drain that curves along the edge of the northern terrace of the granary to the west.
The tank would have been open to the sky, but the surrounding structures would have been roofed. The sidewalls and parts of the floor have been conserved using modern replica bricks.
The side walls of the tank were constructed with finely fitted bricks and a thick layer of bitumen (natural tar) was laid along the sides of the tank to keep water from seeping through the walls and up into the superstructure.
At the foot of the stairs is a small ledge with a brick edging that extends the entire width of the pool. People coming down the stairs could move along this ledge without actually stepping into the pool itself.
The Great Bath was entered using two wide staircases, one from the north and one from the south. The floor of the tank is watertight due to finely fitted bricks laid on edge with gypsum plaster.
The great bath surrounded by a brick colonnade, measures approximately 12 meters north-south and 7 meters wide, with a maximum depth of 2.4 meters.
The Great Bath is situated along a north-south street with a drain covered with limestone blocks. In the background is the so-called Granary, while in the foreground are the walls of several domestic structures.