Douala Maritime Museum gives useful context to the thing that made the city: water. The exhibits trace the Wouri estuary, coastal navigation, fishing, colonial trade, and the growth of the modern port, with models and photographs that help make sense of the busy waterfront outside.
It is not a large museum, but it fills an important gap in Douala, where the port is everywhere and yet hard for visitors to read. Pair it with a walk around Bonanjo and the nearby public-art works for a compact introduction to the city.