Engaruka is an abandoned system of ruins in the Great Rift Valley of northern Tanzania (2°58′58.80″S 35°57′0.00″E / 2.983°S 35.95°E / -2.983; 35.95Coordinates: 2°58′58.80″S 35°57′0.00″E / 2.983°S 35.95°E / -2.983; 35.95), famed for its irrigation and cultivation system. It is considered one of the most important Tanzanian archaeological sites.

Sometime in the fifteenth century, an iron age farming community with a large continuous village area on the footslopes of the Rift Valley escarpment, housing several thousand people developed an intricate irrigation and cultivation system, involving a stone-block canal channelling water from the "Crater Highlands" rift escarpment to stonelined cultivation terraces (Stump, Daryl 2006, Laulumaa, Vesa 2006). Measures were taken to prevent soil erosion and the fertility of the plots was increased by using the manure of stall fed cattle. For an unknown reason Engaruka was abandoned at latest in mid-19th century. The site still poses many questions, including the identity of the founders, how they developed such an ingenious farming system, and why they left (Stump, Daryl 2003). The site has been linked to the Sonjo, a people living some 60 miles to the northwest known for their use of irrigation systems in agriculture and similar terraced village sites (Nurse, Derek & Rottland, Franz 1991). New studies have revealed lot of unknown perspectives of the past of Engaruka, for example the Middle Stone Age and Neolithic Stone Age occupation history of the area (Seitsonen, Oula 2005).

"Medicine man" or "medicine woman" are English terms used to describe traditional healers and spiritual leaders among Native American and other indigenous or aboriginal peoples. Anthropologists tend to prefer the term "shaman," a specific term for a spiritual mediator from the Tungusic peoples of Siberia.

The primary function of these "medicine elders" (who are not always male) is to secure the help of the spirit world, including the Great Spirit (Wakan Tanka in the language of the Lakota Sioux), for the benefit of the entire community.

Sometimes the help sought may be for the sake of healing disease, sometimes it may be for the sake of healing the psyche, sometimes the goal is to promote harmony between human groups or between humans & nature. So the term "medicine man/woman" is not entirely inappropriate, but it greatly oversimplifies and also skews the depiction of the people whose role in society complements that of the chief. These people are not the Native American equivalent of the Chinese "barefoot doctors", herbalists, nor of the emergency medical technicians who ride rescue vehicles.