The site takes its name from a modern village located near the former course of the Ravi River.
The site of the ancient city contains the ruins of a Bronze Age fortified city, which was part of the Cemetery H culture and the Indus Valley Civilization, centered in Sindh and the Punjab.
The city is believed to have had as many as 23,500 residents and occupied over 100 hectares (250 acres) at its greatest extent during the Mature Harappan phase (2600–1900 BC), which is considered large for its time.
The two greatest cities, Mohenjo-daro and Harappa, emerged circa 2600 BCE along the Indus River valley in Punjab and Sindh.
The civilization, with a writing system, urban centers, and diversified social and economic system, was rediscovered in the 1920s after excavations at Mohenjo-daro in Sindh near Larkana, and Harappa, in west Punjab south of Lahore.
A number of other sites stretching from the Himalayan foothills in east Punjab, India in the north, to Gujarat in the south and east, and to Balochistan in the west have also been discovered and studied.
Although the archaeological site at Harappa was damaged in 1857 when engineers constructing the Lahore-Multan railroad (as part of the Sind and Punjab Railway), used brick from the Harappa ruins for track ballast, an abundance of artifacts has nevertheless been found.
In 1856, General Alexander Cunningham, later director general of the archaeological survey of northern India, visited Harappa where the British engineers John and William Brunton were laying the East Indian Railway Company line connecting the cities of Karachi and Lahore.
John wrote: “I was much exercised in my mind how we were to get ballast for the line of the railway”.
They were told of an ancient ruined city near the lines, called Brahminabad.
In 1872–75 Alexander Cunningham published the first Harappan seal (with an erroneous identification as Brahmi letters).
It was half a century later, in 1912, that more Harappan seals were discovered by J. Fleet, prompting an excavation campaign under Sir John Hubert Marshall in 1921–22 and resulting in the discovery of the civilization at Harappa by Sir John Marshall, Rai Bahadur Daya Ram Sahni and Madho Sarup Vats, and at Mohenjo-daro by Rakhal Das Banerjee, E. J. H. MacKay, and Sir John Marshall.
By 1931, much of Mohenjo-Daro had been excavated, but excavations continued, such as that led by Sir Mortimer Wheeler, director of the Archaeological Survey of India in 1944.
Among other archaeologists who worked on IVC sites before the independence in 1947 were Ahmad Hasan Dani, Brij Basi Lal, Nani Gopal Majumdar, and Sir Marc Aurel Stein.
As seen in Harappa, Mohenjo-Daro and the recently partially excavated Rakhigarhi, this urban plan included the world’s first known urban sanitation systems: see hydraulic engineering of the Indus Valley Civilization.
Within the city, individual homes or groups of homes obtained water from wells.
From a room that appears to have been set aside for bathing, waste water was directed to covered drains, which lined the major streets.
Houses opened only to inner courtyards and smaller lanes.
The house-building in some villages in the region still resembles in some respects the house-building of the Harappans.