Major concentrations of Fulani people exist in the Fouta Djallon highlands of central Guinea and south into the northernmost reaches of Sierra Leone; the Futa Tooro savannah grasslands of Senegal and southern Mauritania; the Macina inland Niger river delta system around Central Mali; and especially in the regions around Mopti and the Nioro Du Sahel in the Kayes region; the Borgu settlements of Benin, Togo, and West-Central Nigeria; the northern parts of Burkina Faso in the Sahel region's provinces of Seno, Wadalan, and Soum; and the areas occupied by the Sokoto Caliphate, which includes what is now Southern Niger and Northern Nigeria (such as Tahoua, Katsina, Sokoto, Kebbi, Zinder, Bauchi, Diffa, Yobe, Gombe, and further east, into the Benue River valley systems of North Eastern Nigeria and Northern Cameroon).