Tanzania is home to one of the world's largest remaining elephant populations. The majority of these elephants can be found in the remote and breathtakingly beautiful Selous Game Reserve, which is a World Heritage Site. The name comes from hunter-explorer Frederick Courtenay Selous, who was also a naturalist and conservationist in addition to a hunter. During the First World War, he was killed in the Reserve's Beho Beho region. The Reserve, which is larger than Switzerland, is Africa's largest and second only to the Serengeti in terms of wildlife concentration. The Reserve's terrain is varied, with rolling savannah woodland, grassland plains, and rocky outcrops. Crocodile, buffalo, hippopotamus and a wild dog can also be seen here. The Reserve is accessible by road, air charter, and rail (Tazara) from Dar-Es-Salam, and the best time to visit is between the end of June and the end of October. Walking safaris can be taken from the Reserve's camps in the company of an armed guard