Mayotte
Description
Officially part of France, Mayotte is a small group of islands between Mozambique and Madagascar, consisting of a main island, Grande-Terre (or Mahoré), a smaller island, Petite-Terre (or Pamanzi), and several islets around these two. Geographically it is the most southern of the Comoros Islands, but contrary to the rest of the Comoros, Mayotte chose to remain French.
It is possible to hike up Mount Choungui. And being French territory, of course there is a GR 1: Tour de Mayotte, a 170 km long circular trail all around the island.