Architecture and Town Planning
If by we mean the tendency to form society, founding cities with all their attendant rules, then the Harappan people succeeded admirably. Excavations show a degree of urban planning which the Romans achieved only later, after a gap of 2500 years.
The twin cities of Mohenjo-daro and Harappa formed the hub of the civilization. They are representative in the sense that planning principles employed here are followed practically without change at all other sites. Both cities were a mile square, with defensive outer walls. An orthogonal street layout was oriented toward the cardinal directions. The street layout shows an understanding of the basic principles of traffic, with rounded corners to allow the turning of carts easily. These streets divided the city into 12 blocks.
The Harappan house is an amazing example of a native people, without the benefit of technology, adapting to local conditions and intuitively producing an architecture eminently suited to the climate. The house was planned as a series of rooms opening on to a central courtyard. This courtyard served the multiple functions of lighting the rooms, acting as a heat absorber in summer and radiator in winter, as well as providing an open space inside for community activities. There were no openings toward the main street, thus ensuring privacy for the residents. In fact, the only openings in the houses are rather small - this prevented the hot summer sun heating the insides of the houses.
An advanced drainage system is also in evidence. Drains started from the bathrooms of the houses and joined the main sewer in the street, which was covered by brick slabs or corbelled brick arches, depending on its width. In most of the sites, the central-western blocks were reserved for public architecture. Perhaps the most famous examples are the Great Bath and Granary at Mohenjo-daro. The Great Bath has been the subject of much debate over its exact function. The prevalent view seems to be that it was used for ritualistic bathing - much as continues in the Hindu tradition even today. It is unfortunate that none of the structures of the Indus Valley civilization survive intact today.
Unlike Egypt and Mesopotamia, the Harappan people left nothing monumental, like the pyramids or ziggurats, for posterity to marvel at. This may be the reason that among the majority of books on architecture, the Harappan Culture hardly merits a note. However, the planning principles and response of the architecture to climate are a lesson to us all.