Halfway to Lake Natron, on the eastern edge of the Ngorongoro Conservation Area, lies this 300- to 500-year-old ruin of a farming town that developed a complex irrigation system with terraced stone housing sites. Although the ruins are historically significant, casual visitors are likely to be more impressed with the up-close views of the escarpment than the vaguely house-shaped piles of rocks.
Archaeologists are unsure of Engaruka's origins, although some speculate that the town was built by ancestors of the Iraqw (Mbulu) people, who once populated the area and now live around Lake Eyasi. Others propose it was the Sonjo, a Bantu-speaking people.
Knowledgeable English-speaking guides (no set prices) for the ruins or other walks in the area, including a one-day climb of nearby Kerimasi, can be found at Engaruka Ruins Campsite, or they can be arranged in advance through the Tanzania Tourist Board Tourist Information Centre in Arusha. It's also worth contacting the Engaruka Cultural Tourism Program, which arranges visits to Maasai villages and other local attractions, as well as climbs up Kerimasi and Ol Doinyo Lengai.
The ruins are unsigned above the village of Engaruka Juu. Turn west at Engaruka Chini, a smaller village along the Lake Natron road, and follow the rough track 4.5km until you reach Engaruka Juu Primary Boarding School.