The dormant volcano of Mount Rungwe, rising to 2,961 metres above sea level rises above the town, a part of the Great Rift Valley. Much of the mountain's area contains forest reserve, established as reserve by the British in 1949. Rungwe has unbroken 10−15 m closed-canopy forest up to the treeline at 2600 m, and is home to numerous important bird species. The bamboo zone starts at 1900 metres, and bamboo wood is extensively used by local people. The mountain forest has spiritual significance for the Wanyakyusa people( locally called 'Isyeto'). A lava flow from Mount Rungwe formed a natural bridge called Daraja la Mungu or the Bridge of God on the Kiwira River, which is fast-flowing and borders the Ileje mountain ranges. Other notable topographic features are the Masoko Crater and the Kaporogwe Falls. Rungwe's ridge falls north-west to merge into the Poroto Mountains.