Mongomo is a town in the province of Wele-Nzas on mainland Equatorial Guinea, on the eastern border, roughly 1 km west of Gabon's Woleu …Mongomo is a town in the province of Wele-Nzas on mainland Equatorial Guinea, on the eastern border, roughly 1 km west of Gabon's Woleu-Ntem Province. The president of Equatorial Guinea, Teodoro Obiang Nguema Mbasogo, was born in Mongomo.