The Mahale Mountains, surrounding Lake Tanganyika, are home to some of Africa's last remaining wild chimps: a group of about 800, acclimated to human visitors by a Japanese research effort begun in the 1960s. To reach there, take a steamer from Kigoma and then a local fishing boat.

Mahale chimp tracking is a beautiful experience. The guide's eyes pick out last night's nests - dark bunches high in a gallery of trees crowding the sky. Scraps of half-eaten fruit and fresh dung provide crucial clues that go further into the forest. Butterflies glide across the dappled sunlight. Then you're in their midst, combing each other's shiny coats at close quarters, arguing loudly, or springing into the trees to swing freely.

While chimpanzees are the main attraction, the slopes are home to a varied forest wildlife that includes readily visible battalions of red colobus, red-tailed and blue monkeys, and a kaleidoscope variety of colorful forest birds. The park also has an indigenous race of Angolan colobus monkeys, which may be seen on the high grassy peaks dotted with alpine bamboo.