[1] The Commune of Kirundo has an area of 207.3 square kilometres (80.0 sq mi) and had a population of 93,110 as of the 2008 census.

Marshes extend northwest from the reserve to the Akanyaro River, which forms the border with Rwanda.

[3] Lake Rwihinda has been threatened by lack of rain since 1999 and excessive evapotranspiration.

[4] Settlements include the provincial capital of Kirundo; Rutare, to the north of the airport; and Mutwenzi, near to the Mutwenzi military base.

Kirundo is divided into 22 collines, from north to south:[5]