"Mohenjo-daro was discovered in 1922 by R. D. Banerji, an officer of the Archaeological Survey of India, two years after major excavations had begun at Harappa, some 590 km to the north. Large-scale excavations were carried out at the site under the direction of John Marshall, K. N. Dikshit, Ernest Mackay, and numerous other directors through the 1930s. Although the earlier excavations were not conducted using stratigraphic approaches or with the types of recording techniques employed by modern archaeologists they did produce a remarkable amount of information that is still being studied by scholars today. The last major excavation project at the site was carried out by the late Dr. G. F. Dales in 1964-65, after which excavations were banned due to the problems of conserving the exposed structures from weathering."

Mohenjo-Daro - An Ancient Indus Valley Metropolis

"While some scholars have argued for a sudden emergence of a vast array of technologies associated with the urban integration of the Indus Valley civilization around 2600 BC (Possehl 1997), the current evidence suggests that this was not the case. The contrast between the Early Harappan and Harappan phase is not so much the presence or absence of specific technologies, but rather the ways in which specific technologies were used. During the Kot Diji Phase, around 2800 BC, we see the first elaboration of technologies such as faience working and seal carving. These crafts were undoubtedly associated with the emergence and consolidation of new social groups that used specific types of artifacts to distinguish themselves and their ideologies. The presence of similar crafts in the two adjacent walled areas at Harappa suggest that crafts played a very important role in legitimation of competing merchants and other elites."

Early Developments of Art, Symbol, and Technology in the Indus Valley Tradition - Jonathan Mark Kenoyer

Mohenjo-daro is a remarkable construction, considering its antiquity. It has a planned layout based on a grid of streets, which were laid out in perfect patterns. At its height the city probably had around 35,000 residents. The buildings of the city were particularly advanced, with structures constructed of same-sized sun dried bricks of baked mud and burned wood.

The public buildings of these cities also suggest a high degree of social organization. The so-called great granary at Mohenjo-daro as interpreted by Sir Mortimer Wheeler in 1950 is designed with bays to receive carts delivering crops from the countryside, and there are ducts for air to circulate beneath the stored grain to dry it. However, Jonathan Mark Kenoyer has noted though, that no record of grain exists at the "granary." Thus Kenoyer suggests that a more appropriate title would be "Great Hall."

Close to the granary, there is a building similarly civic in nature - a great public bath, with steps down to a brick-lined pool in a colonnaded courtyard. The elaborate bath area was very well built, with a layer of natural tar to keep it from leaking, and in the centre was the pool. Measuring 12m x 7m, with a depth of 2.4m, it may have been used for religious or spiritual ceremonies.

Within the city, individual homes or groups of homes obtained water from wells. Some of the houses included rooms that appear 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. A variety of buildings were up to two stories high.

Being an agricultural city, it also featured a large well, and central marketplace. It also had a building with an underground furnace (hypocaust), possibly for heated bathing.

Mohenjo-daro was a well fortified city. Lacking actual city walls, it did have towers to the west of the main settlement, and defensive fortifications to the south. Considering these fortifications and the structure of other major Indus valley cities like Harappa, lead to the question of whether Mohenjo-daro was an administrative centre. Both Harappa and Mohenjo-daro share relatively the same architectural layout, and were generally not heavily fortified like other Indus Valley sites. It is obvious from the identical city layouts of all Indus sites, that there was some kind of political or administrative centrality, however the extent and functioning of an administrative centre remains unclear.

Mohenjo-daro was successively destroyed and rebuilt at least seven times. Each time, the new cities were built directly on top of the old ones. Flooding by the Indus is thought to have been the cause of destruction.

The city was divided into two parts, the so-called Citadel and the Lower City. Most of the Lower City is yet to be uncovered, but the Citadel is known to have the public bath, a large residential structure designed to house 5,000 citizens and two large assembly halls.

Mohenjo-daro, Harappa and their civilization, vanished without trace from history until discovered in the 1920s. It was extensively excavated in the 1920s, but no in-depth excavations have been carried out since the 1960s.

Source: http://en.wikipedia.org/wiki/Mohenjo_Daro