The Twa are a forest-dwelling pygmy people descended from Rwanda's earliest inhabitants.
Scholars disagree on the origins of and differences between the Hutu and Tutsi; some believe differences are derived from former social castes within a single people, while others believe the Hutu and Tutsi arrived in the country separately, and from different locations.
Rwanda is in the African Great Lakes region and is highly elevated; its geography is dominated by mountains in the west and savanna to the east, with numerous lakes throughout the country.
The climate is temperate to subtropical, with two rainy seasons and two dry seasons each year.
Rwanda is one of only two countries in which mountain gorillas can be visited safely, and visitors pay for gorilla tracking permits.