Great Bath

The earliest known public water tank of the ancient world, located at the Mohenjo-daro citadel in Sindh, Pakistan. Built c. 2500 BC during the Indus Valley Civilization, it measures 12 metres long, 7 metres wide, and 2.4 metres deep. The brick-built pool was waterproofed with a lining of natural bitumen (tar) and accessed by steps from a colonnaded courtyard. Believed to have served ritual purification purposes, it reflects the civilization's advanced urban planning and emphasis on hygiene -- Mohenjo-daro featured extensive sewage systems and baths in most homes.