English: The Great Bath. A 2.4m deep, 12m long, and 7m wide pool known as "The Great Bath" is located at the centre of the Citadel, is made of fine baked waterproof mud bricks and a thick layer of bitumen (natural tar – presumably to keep water from seeping through the walls), which indicates that it was used for holding water. Many scholars have suggested that this huge deep bath could have been a place for ritual bathing or religious ceremonies. It is the earliest public water tank of the ancient world. Adjacent to it are a well that was used to supply water to the bath.