A breakthrough LiDAR survey in the dense wetlands of the Niger Delta has identified a sprawling, fortified archipelago-city dating to the 6th century CE. The mapping reveals a series of interconnected artificial islands, each protected by a complex system of earthen embankments and submerged wooden palisades that once formed a massive defensive perimeter around a central residential citadel.
This 'Island Citadel' discovery challenges existing models of West African urbanism, suggesting that early maritime cultures in the delta had developed advanced hydro-engineering techniques to manage seasonal flooding. The survey also mapped nearly 50 kilometers of straightened mangrove channels, which researchers believe served as high-speed aquatic corridors for trade and military maneuvers between the delta and the hinterlands.