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Before the excavation of Harappan cities, scholars thought that Indian civilization had begun in the Ganga valley as Aryan immigrants from Persia and central Asia populated the region around 1250 BCE. The discovery of ancient Harappan cities unsettled that conception and moved the timeline back another 1500 years. situating the Indus Valley Civilization in an entirely different environmental context.

Harappa was a fortified city in modem-day Pakistan and is believed to have been home to as many as 23,500 residents living in sculpted houses with flat roofs made of red sand and clay. The city spread over 150 hectares - 370 acres - and had fortified administrative and religious centres of the same type med in Mohenjo-Daro. Both cities had similar organization and featured citadels, central areas in a city that were heavily fortified - protected with defensive military structures. Additionally, both cities were situated along the Indus River. This structure would have allowed those at the higher levels of the buildings in either city to look down the river and see into the distance.