THE EASTERN ARC
Stretching from the Taita Hills of southern Kenya to the southern highlands of Tanzania, the Eastern Arc Mountain Range has some of the oldest geological activity on the continent. Estimated to be at least 100 million years old – with some formations up to 600 million years old – the relative stability of their climate means that the area hosts a surprising array of biodiversity, from plant and insect life, to spectacular bird species.

The Eastern Arc Mountains are the sweeping column of ancient, crystalline hills, escarpments and mountains that file South-East from Kilimanjaro in a verdant bi-section of the arid Masai Steppe. The Eastern Arcs are cloaked in fertile rainforests, and shadowed by open plains in which very individual natural phenomena and distinctive human cultures have been allowed to ripen into a blossoming low-impact eco-tourist destination.

The Eastern Arc Mountains are a chain of 12 mountain blocks in Kenya and Tanzania that are influenced by the Indian Ocean . The mountain chain is a series of isolated mountains, which have been heavily covered by forests. Much of the original forests, especially at the more accessible or lower elevations, have been converted for agricultural crops. These mountains are recognized as one of 24 globally important "hot spots" for forest biodiversity according to Conservation International. These mountains also serve as water catchments for urban areas such as Dar es Salaam, Tanga, and Morogoro , Tanzania. The forests provide firewood, medicinal plants, lumber, and other forest-related products. Local villagers depend on these forests to live. In place of closed mountain forests is now a patchwork of forest fragments and agriculture.

In Tanzania , water flowing from the Eastern Arc forests is the source of 90 percent of the country's hydroelectric power. The forests are also the source of water for major cities. While the Eastern Arc forests once covered more than 23,000 square kilometers in both Kenya and Tanzania, more recent estimates place the remaining forest cover as low as 2,000 square kilometers. Five monkey species and at least four species of prosimian primates are unique, or endemic, to this region. Found only along the Tana River in Kenya, the Tana River red colobus is Critically Endangered. Only 1,000-1,200 of the Critically Endangered Zanzibar red colobus remain in the wild. The region is home to 20 out of 21 species of the African violet, which form the basis of a global houseplant trade.