<P> The site of the ancient city contains the ruins of a Bronze Age fortified city, which was part of the Indus Valley Civilization centered in Sindh and the Punjab, and then the Cemetery H culture . The city is believed to have had as many as 23,500 residents and occupied about 150 hectares (370 acres) with clay brick houses at its greatest extent during the Mature Harappan phase (2600--1900 BC), which is considered large for its time . Per archaeological convention of naming a previously unknown civilization by its first excavated site, the Indus Valley Civilization is also called the Harappan Civilization . </P> <P> The ancient city of Harappa was heavily damaged under British rule, when bricks from the ruins were used as track ballast in the construction of the Lahore--Multan Railway . In 2005, a controversial amusement park scheme at the site was abandoned when builders unearthed many archaeological artifacts during the early stages of building work . A plea from the Pakistani archaeologist Mohit Prem Kumar to the Ministry of Culture resulted in a restoration of the site . </P> <P> The Harappan Civilization has its earliest roots in cultures such as that of Mehrgarh, approximately 6000 BC . The two greatest cities, Mohenjo - daro and Harappa, emerged circa 2600 BC along the Indus River valley in Punjab and Sindh . The civilization, with a possible writing system, urban centers, and diversified social and economic system, was rediscovered in the 1920s also 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 Pakistani 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 have nevertheless been found . The bricks discovered were made of red sand, clay, stones and were baked at very high temperature . As early as 1826 Harappa, located in west Punjab, attracted the attention of a British officer in India, who gets credit for preliminary excavations in Harappa . </P> <P> The 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 Harappa are generally characterized as having "differentiated living quarters, flat - roofed brick houses, and fortified administrative or religious centers ." Although such similarities have given rise to arguments for the existence of a standardized system of urban layout and planning, the similarities are largely due to the presence of a semi-orthogonal type of civic layout, and a comparison of the layouts of Mohenjo - Daro and Harappa shows that they are in fact, arranged in a quite dissimilar fashion . </P>

The eastern limit of the harappa culture was