The Kisumu Impala Sanctuary sits right on the shore of Lake Victoria, a small but pleasant reserve covering less than a square kilometre. The impala herd is healthy and easily seen, and there are also waterbuck, vervet monkeys, and a reliable population of hippos in the lake shallows — the same animals that sometimes appear at Hippo Point at sunset.
It is worth combining with a walk along the lakeshore. The views across Lake Victoria from the sanctuary edge are some of the best in the city, and if you time a visit for late afternoon the light on the water is excellent. Boat trips can sometimes be arranged from here.