The most characteristic feature of the Harappan Civilization was its urbanization. The cities show evidence of an advanced sense of planning and organization. Each city was divided into the citadel area where the essential institutions of civic and religious life were located and the residential area where the urban population lived. In the citadel the most impressive buildings were the granaries which were store -houses. Near the granaries were the furnaces where the metal workers produced a variety of objects in metals such as copper, bronze, lead and tin. The potters also worked in this part. The workers lived together in small quarters near the factory. Another well-known building was the Great Bath. It might have served the purpose of ritual bathing vital to any religious ceremony in India. In Mohenjo daro there is also a large building which appears to have been the house of the governor. Another building nearby was either a meeting hall or a market place. Below the citadel in each city lay a town proper.
The town was extremely well planned. The street ran straight and at right angles to each other following the grid system. The rectangular town planning was unique to the Harappans and was not known in Mesopotamia or Egypt. The streets were very wide and the houses built of burnt bricks lined both sides of the street. In Egypt and Mesopotamia dried or baked bricks were used. The houses were of varying sizes which suggest class differences in Harappan society. A well laid drainage system kept the cities clean.