In Ethiopia, there are so many and big lakes along, called, Rift Valley area. The lake Langano is safe enough for entertainment in it. Everybody can enjoy swimming, boating, fishing, and any other inner-lake activities. Refer to UNDP health guide (may be obsolete, though)
It was the first rural area visit upon my arrival in Addis (July 1999). Experiencing wildlife and staying with local residents could be enough cultural shock on me. More understanding of people and way of their life kept me inside their society even in Addis Ababa. Though physical condition was unfavorable (I am afraid, still is), excursion to Langano lake became the central part of life long memory.