Wander by the water and breathe some fresh air at Mamoudzou Harbour. It's always nice watching the boats as they come and go.
If you're planning to stick around a while in Mamoudzou, Mamoudzou Harbour is an interesting place to start your sightseeing. This place for ships to anchor is one of many attractions that'll keep you on the go here. Moya Beach, Lake Dziani, and Jumbo Score are also waiting for you nearby.