Mohenjo-daro (literally, "mound of the dead"), like Harappa, was a city of the Indus Valley civilization. It is somewhat better preserved than Harappa, and therefore a more informative source on its parent civilization. It was probably built between four and five thousand years ago, and was abandoned around 1700 BCE, probably due to a change of course of the river which supported the civilization. It was rediscovered in the 1920s by archaeologists.
Mohenjo-daro is a remarkable construction, considering its antiquity. It has a planned layout based on a grid of streets, with structures constructed of bricks of baked mud, sun dried bricks and burned wood. At its height the city probably had around 35,000-40,000 residents. It had an advanced drainage system, a variety of buildings up to two stories high, and an elaborate bath area. The bath area was very well built and had a layer of natural tar, to keep it from leaking. Being an agricultural city, it also featured a large well, granary, and central marketplace. Perhaps most unexpected, it even had a building with an underground furnace (hypocaust), possibly for heated bathing.
The city 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.
Mohenjo-daro is in what is now northwest Sind in Pakistan.
Trivia
Gottfried de Purucker remarked (referring to Secret Doctrine, vol.2, p.417): A highly advanced urban civilization of Mohenjo Daro has been discovered on the Indus "between Attock and Sind," exactly the location mentioned in The Secret Doctrine as the abode of the Aethiopians. (Encyclopedic Theosophical Glossary: Aethiopians)
Mohenjodaro, one of the largest metropolises, was built on the west bank of the river.
Mohenjodaro is not the original name, of course, but one given by local villagers referring to the 'mound of the dead': the tower and hillocks of abandoned debris of bricks that they had their forefathers had noticed in the surroundings.
Kot Diji is 40 kilometers east of Mohenjodaro; Chanhu-daro (128 kilometers south of Mohenjodaro) bears evidence of a later phase of the civilization, and it would appear that the inhabitants had to move away from the older metropolises and set up shoddy settlements in nearby areas where conditions, economic and environmental, were still favourable.