Iringa is a city in Tanzania with a population of 112,900 (as of 2004[update]). It is situated at a latitude of 7.77°S and longitude of 35.69°E. The name is derived from the Hehe word lilinga, meaning fort. Iringa is the administrative capital of Iringa Region. It has many established industries, including manufacturing and food processing. Most of its electricity comes from the nearby Mtera Dam. Iringa is a minor transport hub, with regular bus service and trucking to Dar es Salaam, Mbeya, Songea, and Dodoma. Iringa was built during the 1890s by the German Army as a defensive base to be used against the Hehe uprising led by Chief Mkwawa. The fortress and headquarters of Chief Mkwawa was situated in the nearby village of Kalenga. The town stretches along a hilltop overlooking the Ruaha River to the south, and spreads along ridges and valleys to the north. The altitude of the town's environs is more than 1550 meters (5000 feet) above sea level. The months of June, July, and August can see low temperatures near freezing. The Tanzam Highway passes through the valley below the town; the highway distance from Iringa's limits to Dar es Salaam is 502 kilometers (312 mi), via Morogoro. The Isimila Stone Age site, which lies about 20 km (12 mi) to the southwest, contains archeological artifacts, particularly stone tools, from human habitation about 70,000 years ago. Iringa Urban Municipality is the administrative designation of the Municipality of Iringa. The six districts in the Iringa Region include Mufindi, Makete, Ludewa, Kilolo and Iringa Municipal.