The Great Bath is part of a large citadel complex that was found in the 1920s during excavations of Mohenjo-daro, one of the main centres of the Indus civilization. The bath is built of fine brickwork and measures 897 square feet (83 square metres). It is 8 feet (2.5 metres) lower than the surrounding pavement. The floor consists of two skins of sawed brick set on edge in gypsum mortar, with a layer of bitumen sealer sandwiched between the skins. Water was evidently supplied by a large well in an adjacent room, and an outlet in one corner of the bath led to a high corbeled drain that disgorged on the west side of the mound. The bath was reached by flights of steps at either end, originally finished with timbered treads set in bitumen.