The ancient moat system that once encircled the Benin Empire is one of the most remarkable feats of engineering in African history. The Iya, as it is known in Edo, was a massive earthwork of ditches and banks that protected the city and its surroundings — not a single moat but an interconnected system of fortifications built over several centuries, some sections rising to over 17 metres in height.
Much of the moat has been lost to urban growth, encroachment, and neglect. But surviving sections can still be seen within the city, particularly in older residential areas where the landscape still rises and falls with the ancient earthworks. The city is working to preserve and document what remains. Seeing the moat requires local knowledge of where the visible sections are — ask at the museum or hire a local guide.