This ancient settlement existed from about 3300 BCE and is believed to have had as many as 40,000 residents—considered large for its time. Although the Harappa Culture extended well beyond the bounds of present day Pakistan, its centres were in Sindh and the Punjab.
In 2005 a controversial amusement park scheme at the site was abandoned when builders unearthed many archaeological artifacts during the early stages of construction work. A plea from the prominent Pakistani archaeologist Ahmed Hasan Dani to the Ministry of Culture resulted in a restoration of the site.
The Indus Valley civilization (also known as Harrappan culture) has its earliest roots in cultures such as that of Mehrgarh, approximately 6000 BCE. The two greatest cities, Mohenjo-Daro and Harrappa, 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 (which means "mound of the dead") in Sindh near Sukkur, and Harrappa, 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 Harrappa was partially damaged in 1857 when engineers constructing the Lahore-Multan railroad used brick from the Harrappa ruins for track ballast, an abundance of artifacts have nevertheless been found.
Indus Valley civilization was mainly an urban culture sustained by surplus agricultural production and commerce, the latter including trade with Sumer in southern Mesopotamia. Both Mohenjo-daro and Harrappa were built according to similar plans of well-laid-out streets, "differentiated living quarters, flat-roofed brick houses, and fortified administrative or religious centers." Weights and measures were roughly the same (though not fully standardized) throughout the area and distinctive seals were used, among other applications, for identification of property and shipment of goods. Although copper and bronze were in use, iron was still not employed. "Cotton was woven and dyed for clothing; wheat, rice, and a variety of vegetables and fruits were cultivated; and a number of animals, including the humped bull, were domesticated." Wheel-made pottery—some of it adorned with animal and geometric motifs—has been found in profusion at all the major Indus sites. A centralized administration for each city, though not the whole civilization, has been inferred from the revealed cultural uniformity; however, it remains uncertain whether authority lay with a priestly or a commercial oligarchy.
By far the most exquisite but most obscure artifacts unearthed to date are the small, square steatite seals engraved with human or animal motifs. Large numbers of the seals have been found at Mohenjo-daro, many bearing pictographic inscriptions generally thought to be a kind of script. Despite the efforts of philologists from all parts of the world, however, and despite the use of computers, the script remains undeciphered, and it is unknown if it reflects proto-Dravidian or proto-Sramanic or some other language(s) like Brahmi, Brahui.
There were other highly developed cultures in adjacent regions of Baluchistan, Central Asia and peninsular India. Material culture and the skeletons from the Harrappa cemetery and other sites testify to a continual intermingling of communities from both the west and the east. Harrappa was settled before what we call the ancient Indus civilization flourished, and it remains a living town today.