One of the world's largest enclosed coral lagoons
Mayotte's main islands are encircled by a barrier reef enclosing one of the largest lagoons in the world. Green turtles graze on seagrass in the shallows off N'Gouja beach, where snorkellers can swim alongside them, and dolphins are common. From about July to October humpback whales come into the lagoon to breed and calve. On Petite-Terre, Lake Dziani fills a volcanic crater, and Mamoudzou, on Grande-Terre, is the main town and ferry point. Mount Choungui gives a steep climb with lagoon views.