“ MFUMBIRO, or Kirunga, general names for a chain of volcanic mountains extending across the Central African, or Albertine, rift-valley immediately north of Lake Kivu. The range, the result probably of recent geological changes, completely blocks the valley at this point, forming a divide between the rivers flowing north to the Nile and the waters of Lake Kivu connected through Tanganyika with the Congo system. The chain consists of two groups of mountains, surrounded by a vast lava field. The western group lies directly north of Lake Kivu. ”

“ The eastern peaks are snowclad for a part of the year. North of these high mountains is a district, extending towards Albert Edward Nyanza, containing hundreds of low peaks and extinct volcanoes. It is to this region that the name Umfumbira or Mfumbiro is said properly to belong. ”