Mohenjo-daro

The excavated ruins of Mohenjo-daro occupy a low plateau above the Indus floodplain, and the approach across the flat Sindhi countryside gives no warning of what lies ahead: suddenly the ground rises and you are walking streets that were laid out by a Bronze Age city planner who had no known connection to Egypt, Mesopotamia or the Indus's own contemporaries, making the urban sophistication here feel like a solitary achievement in human history.

The Great Bath — a large rectangular tank flanked by colonnades — is the most discussed structure and the most visually striking: its brick vaulting, the staircases descending to water level and the completeness of its preservation suggest a public institution of a sophistication that does not fit easily into the standard narrative of Bronze Age society, and its exact function remains a matter of scholarly debate.

Walking the grid of streets reveals the logic of the city's planning: brick drainage channels running beneath the paved streets, the raised Citadel mound to the west, and the residential lower city spread out in blocks that were clearly differentiated by function and probably by class, with the largest houses positioned closest to the Citadel in what appears to be a deliberate social hierarchy expressed through urban space.

The scale is modest by the standards of later empires — the largest structures are no more than a few storeys high — but the uniformity of the brickwork and the regularity of the street grid create an urban environment that feels more consciously designed than many ancient cities, and the engineering of the drainage system in particular shows a civic intelligence that was not matched for centuries after the city was abandoned.

The archaeological museum at the site holds finds that humanise the city: jewellery, toys, figurines, and weights that suggest a society engaged in long-distance trade and standardising measurements across its territory, and the absence of obvious military structures or weapons in the archaeological record has given rise to theories about the Indus Valley Civilisation as a notably peaceful urban society.

The collapse of Mohenjo-daro around 1900 BCE remains one of archaeology's unresolved questions; theories include river avulsion, climate change and the decline of the trade networks that sustained the settlement, and the fact that the Indus script remains undeciphered means that we cannot read the records the civilisation itself left behind.

The site is partially covered and some structures are in danger of deterioration from salt efflorescence and moisture; the conservation challenge is acute given the site's immense historical importance and the limited resources available, and visitors who return after several years sometimes note visible changes in the state of exposed brickwork.

Mohenjo-daro is one of the earliest and most planned urban centres in human history, demonstrating civic organisation — street grids, sewers, standardised bricks — that was not surpassed in scale for centuries.

The UNESCO World Heritage inscription in 1980 reflects the site's global significance as evidence of a literate, trading civilisation that developed independently of Mesopotamia and Egypt.

The Great Bath and the associated elite architecture suggest a level of communal ritual and civic organisation that challenges simple hierarchies of ancient urban development.