The Cirque de Mafate is a caldera on Reunion Island (France; located in the Indian Ocean). It was formed from the collapse of the large shield volcano the Piton des Neiges.
The very remote and inaccessible cirque was settled in the 19th century by maroon slaves (i.e. slaves who had escaped from their masters), then later by poor white laborers. It owes its name to one maroon leader.
The cirque is entirely enclosed by mountains, especially tall cliffs, known as remparts, save for the sole river exiting, the Riviere des Galets (river of the pebbles). Inside the cirque, there are considerable declivities. The ilets are pieces of more-or-less flat lands, on which the hamlets are located.
One originality of Mafate is that there are no roads. Because of this, it is a major attraction for hikers willing to experience some unspoiled nature, while still benefiting from grocery stores and other amenities. For this reason, with the impending creation of a national park on the heights of Reunion, it seems very unlikely that roads would be ever built.