The MandaraMountains, which run roughly north-south at the province's Nigerian border, are irregular in that they are volcanic, composed mostly of crystalline and metamorphic rock and granite.
North of Garoua and in the MandaraMountains, where large populations of non-Muslim Kirdi were forced to flee years ago, density peaks at 50 to 100 people per km².
In the MandaraMountains, these circular plots follow the slope of the mountains in terraces.
However, in the past and continuing to this day, these mountains continue to be seen by some as a refuge area where remnants of an earlier civilization whose inhabitants sought refuge from Islamic states are found.
However, the emphasis on the mountains as a refuge area ignores the evidence of a long period of linguistic differentiation in the mountains and of populations that developed and refined sophisticated agricultural techniques that met their needs and an iron technology that gave them some advantage in dealings with their neighbours on the plains.
In December a native of the mountains (and a politician) commented that 'if the people descend to the plains so will the soil.' At least some recognize the importance of the extensive system of terracing found throughout the MandaraMountains.