The most wonderful aspect of the Indus civilization was the excellent town-planning. The Indus civilization was an urban civilization and Mohenjo-daro was the oldest planned city of the world. Both the cities were populous and materially prosperous. The excellent town-planning is in itself a puzzling novelty. The buildings were of baked bricks, some twostoried and some even three-storied. The houses were in one line and the roads and lanes covered the space between the houses. Each house had a yard and was encircled with walls . . . The roads were wide and straight and there was a proper drainage system. The streets were from the north to the south so that the air could work as a sort of suction pump, thereby clearing the atmosphere automatically . . . The excellent drainage system is most attractive. The drains led from individual houses to the back streets and from the back streets by cross drains to the main roads along which many deep drains ran out of the city. —Arun Bhattacharjee, History of Ancient India, 1979