N'djamena, Tchad, is not the top of anyone's destination list. However, if you find yourself in N'djamena, there are fun things to do if you know where to find them! Close to the river, not far from the bridge to Kousseri, Camaroon, is a horse/camel stables where you can rent horses and/or camels. Guides will take you for a ride along the river. I would stay away from the horses as they have not been properly trained, but the camels are safe as you will be led by a guide.
If you are very into horse riding, there is a stables near the airport where the President keeps his Arabian stallions, and some ex-pats keep their horses. If you go there and ask, you might be able to find someone to loan you a horse.