The ancient city of Harappa lies around 150 miles north of Lahore in Pakistan. It was once one of the great centres of a civilisation that has largely disappeared, one with vast trade connections and boasting several of the world's first cities. At a time when another great civilisation was being forged along the banks of the river Nile in Egypt, this much less well-known civilisation was developing on the banks of the Indus Valley.

Neil MacGregor introduces a series of little stone seals that are 4,500 years old, covered in carved images of animals and probably used in trade. The civilisation built over 100 cities, some with sophisticated sanitation systems, large-scale architecture and even designed around a modern grid layout. The renowned modern architect Sir Richard Rogers considers the urban planning of the Indus Valley, and the historian Nayanjot Lahiri looks at how this lost civilisation is remembered, by both modern India and Pakistan.