As anyone who has tried to find a leopard can tell you, they are solitary, secretive and nocturnal animals that are hard to spot.
They spend most of their days hidden in the branches of sausage or acacia trees. The trees also serve as a safe place for the game they have killed, offering protection from lions and hyenas.
In the Serengeti, look carefully in the trees near the Seronera River or other water areas.
Ngorongoro Crater also has a lot of trees along the canyon that offer good viewing opportunities.