At over 21,000km sq, Tsavo is the largest national park in Kenya and indeed one of the largest parks in the world. The magnitude of the park posed an administrational problem and thus was split into two, Tsavo West and Tsavo East. Situated between Nairobi and Mombasa the park is rich in natural splendor with its volcanic hills, four rivers, more than 60 major mammal species and its 1000 plant species. Tsavo West's northern most regions has been developed the most and it has the most spectacular scenery with a rolling volcanic landscape covered in lush bush vegetation. Although the often tall grasses make game spotting more demanding than in other parts of the park, the big five are in residence along with a strong number of antelope. The park's main attractions are the two watering holes, where many lodges have been constructed, pretty much guaranteeing wonderful game viewing for guests. Tsavo East, across the highway from Tsavo West, is famous for its large elephant herds, numbering in over 50. The phenomenal herds of buffalo, with numbers of over 1000 being common here, are another amazing sight. Game viewing is best done along the watercourses and at the Kanderi swamp, not too far from the main Voi gate. Lions are commonly spotted around Aruba Dam, which is 30km from this main gate.