Answer: The earliest and most remarkable evidence of Indian architecture is found in the cities of the Harappan Civilization. The excavations at Harappa and Mohenjo-Daro and several other sites of the Indus Valley Civilization revealed the existence of a modern urban civilization with expert town planning and engineering skills. Harappan architecture symbolic of modern and urban civilization The Harappan people had constructed mainly three types of buildings dwelling houses, pillared halls and public baths. The architecture truly reflected upon the modern planning and engineering acumen of the people as enumerated below: Town Planning:

• Cities were built on a clear geometric pattern or grid layout.
• Roads cut each other at right angles and were very well laid out.
• All the sites consisted of walled cities which provided security to the people. There is evidence also of fortifications with gateways enclosing the walled cities.
• In some sites, there is evidence of citadels or acropolis, perhaps inhabited by ruling class, known as the Upper Town. The lower town consisted of brick houses inhabited by common people.
• There is evidence of buildings of big dimensions with pillared halls and courtyards which perhaps were public buildings, administrative or business centres.
• There is evidence of small one roomed construction that appear to be working people’s quarters.

Building Standards and Material

• Standardised burnt mud bricks were used as building material for houses.
• Many thick layers of well baked bricks laid in gypsum mortar were joined together for the purpose of making the whole construction very strong. The ‘Great Bath’ at Mohenjo Daro is still functional and there is no leakage or cracks in the construction.

Structure of Residential Houses

• Evidence of stairs shows houses were often double storied.
• Doors were in the side lanes to prevent dust from entering the houses.
• Most of the houses had private wells and bathrooms connected to a centralized system.

Drainage System

• Another remarkable feature was the existence of a well-planned drainage system in the residential parts of the city.
• Small drains from the houses were connected to larger ones along the sides of the main roads.
• The drains were covered and loose covers were provided for the purpose of cleaning them.

Thus, the Harappan civilization was truly ahead of age and time in terms of modernity and urban outlook.