Jericho took root beside the freshwater spring of Ein es-Sultan in the Jordan Valley, 250 metres below sea level, just north of the Dead Sea. Around 9500 BCE, the region's hunter-gatherers — the last generations of the Natufian culture — built a permanent village of round mud-brick houses by that spring. Within the following millennium the village hosted what is still one of the most surprising early structures known: a stone wall some four metres high and an attached, internally stepped stone tower, both from the Pre-Pottery Neolithic A layer and dated to roughly 8000 BCE.

The purpose of the wall is still debated. Kathleen Kenyon, who excavated the site in the 1950s, read it as a defensive wall; since then it has also been interpreted as flood protection, a ritual boundary, or a marker of social status. What is certain is that, at a time when agriculture was not yet fully settled and pottery had not yet been invented, a community of a few hundred people coordinated years of skilled stonework. It is the first concrete sign of the shift from small mobile bands to settled societies able to organise collective projects.

The mound was repeatedly destroyed and rebuilt across the next ten thousand years, with each layer rising on the last, through Roman and Byzantine periods. Modern Jericho still draws water from the same spring.