Mang'olaMang'ola is an administrative ward in the Karatu district of the Arusha Region of Tanzania. It is mainly known for its onion farms and for being the onion capital of Tanzania.PopulationAccording to the 2012 census, the ward had a total population of 6,087.Geographylies near the East African Plateau and the Great Rift Valley, approximately 51 km southwest of the town center of Karatu and about 150 km southwest of the city of Arusha.