The Masai Mara lies in the Great Rift Valley, which is a fault line some 3,500 miles (5,600km) long, from Ethiopia's Red Sea through Kenya, Tanzania, Malawi and into Mozambique. Here the valley is wide and a towering escarpment can be seen in the hazy distance. Most of the game viewing activities occur on the valley floor, but some lodges conduct walking tours outside the park boundaries in the hills of the Oloololo Escarpment. The animals are also at liberty to move outside the park into huge areas known as 'dispersal areas'. There can be as much wildlife roaming outside the park as inside. Many Masai villages are located in the 'dispersal areas' and they have, over centuries, developed a synergetic relationship with the wildlife. There are four main types of topography in the Mara: Ngama Hills to the east with sandy soil and leafy bushes liked by black rhino; Oloololo Escarpment forming the western boundary and rising to a magnificent plateau; Mara Triangle bordering the Mara River with lush grassland and acacia woodlands supporting masses of game especially migrating wildebeest; Central Plains forming the largest part of the reserve, with scattered bushes and boulders on rolling grasslands favoured by the plains game In a short stay during the wildebeest migration you could see thousands of animals, at other times there are still hundreds. The plains are full of wildebeest, zebra, impala, topi, giraffe, Thomson's gazelle. Also regularly seen are leopards, lions, hyenas, cheetah, jackal and bat-eared foxes. Black rhino are a little shy and hard to spot but are often seen at a distance. Hippos are abundant in the Mara River as are very large Nile crocodiles, who lay in wait for a meal as the wildebeest cross on their annual quest to find new pastures.