A visit to the -16th century; Fort Jesus in the Old Town is a "must",located on the edge of a coral ridge overlooking the entrance to the Old Port of Mombasa, was built by the Portuguese in 1593 to protect their trade route to India and their interests in East Africa.
bamburi nature park
If you don't want to spend a whole day or more on safari, you can visit the bamburi nature park.
Very nice green surrounding, good guides and lot of animals (most in captivity)
It is nice and relaxing.
see crocodiles, hippos, girafs beeing fed.
giant turtles,monkeys, leguanos, deer in the wild.