french to englishThis yellow sandstone massif, located in the center-west of the island, is made up of high plateaus still partly covered by forest or shrub/herbaceous vegetation typical of the dry environments of western Madagascar . Very significant erosion has carved these plateaus with deep canyons, which contain humid vegetation similar to that of the evergreen forests of eastern Madagascar. However, life has developed in these valleys which are several hundred meters deep, in total autarky for millions of years: there are indeed all the possible ecological niches.

These biotopes, isolated and exempt from any human observation, allowed groups of ancestral animals and plants to differentiate themselves, to the point of giving birth to new species.