The Great Bath is one of the best-known structures among the ruins of the Harappan Civilization, excavated at Mohenjo-daro in present-day Sindh province of Pakistan.
The sloping floor leads to a small outlet at the southwestern corner of the tank, connecting corbelled arch drain, which led the used water out of the bath.
[8] The floor of the tank was watertight due to finely fitted bricks laid on edge with a gypsum plaster, and the side walls were constructed in a similar manner.
To make the tank even more watertight, a thick layer of bitumen (waterproof tar) was laid along the sides of the pool and presumably also on the floor.
[10] Across the street of The Great Bath, there was a large building with several rooms and three verandas, and two staircases leading to the roof and upper floor.