Siuna is a county-sized administrative municipality located in Nicaragua. It is situated approximately 318 kilometres northeast of the capital city, Managua, and 218 kilometres west of Puerto Cabezas, which serves as the regional capital of the North Caribbean Autonomous Region (RACN).
The municipality contains 20 neighborhoods and 204 rural communities. Most of these areas were originally settled to support gold mining operations along the Ei River drainage basin, a process that led to rapid population growth beginning in the mid-1930s.