History is being rewritten at an archaeological site in Morocco. What the discovery of an ancient wall tells us

In the hills of north-west Morocco, overlooking the river that gives the site its name, research at Oued Beht is bringing to light a previously unknown chapter of the region’s past.

The discovery of a substantial built structure suggests that, during the second millennium BC, communities in north-west Africa were actively shaping their environment.

They were also engaging in broader networks of interaction across the Mediterranean world.

Previous research by the Oued Beht Archaeological Project had already brought to light what is likely the earliest and largest agricultural complex ever discovered in Africa outside the Nile Valley.

It dates to around 5,400 to 4,900 years ago.

New excavations carried out in 2023 – in which we took part – have now deepened our understanding of the site.

Our new study shows how we uncovered the earliest known large-scale construction of a probably defensive nature in north Africa beyond the Nile Valley.

It’s about 4,000 to 3,500 years old.

It’s not known exactly what threats these wall-like structures were designed to counter.

They likely relate to increasing competition over land, resources, and possibly control of movement through the landscape, rather than to “invaders”.

Constructions like these suggest communities felt the need to protect themselves or assert power over strategic locations.

This discovery pushes back the evidence for organised defensive architecture in the Maghreb and suggests that societies in this region at this time were more complex and structured than previously believed.

Our study also reveals how the ridge of Oued Beht would become a focal point again in the medieval period, during the 11th to 13th centuries AD.

The same defensive structure was rebuilt, a hamlet or farm was established on a nearby hilltop, and people were buried in a cemetery between the two areas.