From the Wikipedia page 
Manyara Region is one of Tanzania's 31 administrative regions. The regional capital is the town of Babati.
Lake Manyara is in the northern part of the region. It is bordered to the north by the Arusha Region, to the northeast by the Kilimanjaro Region, to the east by the Tanga Region, to the south by the Dodoma Region, to the southwest by the Singida Region, and to the northwest by the Simiyu Region. The highest mountain in the Manyara Region is Mount Hanang.