The territory of Sliven Municipality is 1366 square km and embraces 49 settlements – the towns of Sliven and Kermen and 47 villages.
In Sliven Municipality could be outlined two relief wise regions: semi-mountainous and mountainous on the North and plain – on the South.
Sliven is situated on the outskirts of the Southern slopes and hilly spurs of the Sliven Mountain (1181 m), from which the Eastern part of the Balkan range starts. On the South and the East the town is opened toward the Sliven plain.
Its altitude varies from 180 m up to 300 m.