From the Wikipedia page 
Debub Wollo (Amharic: ደቡብ ወሎ), or South Wollo, is one of 10 Zones in the Amhara Region of Ethiopia. It acquired its name from the former province of Wollo.
Debub Wollo is bordered on the south by Semien Shewa and the Oromia Region, on the west by Mirab Gojjam, on the northwest by Debub Gondar, on the north by Semien Wollo, on the northeast by Afar Region, and on the east by the Oromia Zone and the Argobba special woreda. Its highest point is Mount Amba Ferit. Towns and cities in Debub Wello include Kombolcha, Hayq, Dessie, Wuchale, and Mekaneselam.