СSliven oblast* is situated in South-Eastern Bulgaria, south of the Balkan Mountain, surrounded by a picturesque landscape. With a territory of 3544.066 sq. km it covers 3,19% of the territory of the country which ranks it fifteenth among the twenty-eight oblasts in the Republic of Bulgaria. It is situated 108 km. away from Bourgas – the biggest trade port in Bulgaria where the nearest airport is also located, and 195 km. away from Varna – the second biggest port. It is 288 km. away from the capital.
213 200 people live in Sliven oblast which is 2.8% of the population of the country. Sliven oblast ranks eleventh in the country in terms of population density.
Administratively the oblast is divided into four municipalities – Sliven, Nova Zagora, Kotel and Tvarditsa.
The southern part of the oblast includes a part of the hilly and low mountainous Tundzha river area as well as the plains of Nova Zagora, Kermen and Sliven. The average altitude of Sliven plain is 150 m, whereas it is about 130 m. for Kermen and Nova Zagora plains. In the north they are encompassed by the Balkan Mountain and the far eastern slopes of Sredna Gora Mountain. Chumerna (1536 m), Balgarka (1181 m) and Razboyna (1128 m) are the highest summits in the mountainous part.
Sliven oblast includes areas with temperate continental and transient continental climate due to the Mediterranean influence. It is marked by a short winter and a cool summer.
The hydrological reserves in the oblast are not big. The major water resource is the Tundja river with a catchment basin of about 7 800 sq. km. Its length of 398 km. ranks it fourth among the rivers in Bulgaria. Its waters are used for drinking and irrigation. One of the largest reservoirs in the country, Zhrebchevo, whose capacity exceeds 400 million cubic metres, is constructed on the Tundja river with the main purpose of irrigation. The mineral springs near Sliven and Nova Zagora (the village of Banya) are important hydrological resources around which spa resorts have been built. Sliven Spa is a resort of national significance, whereas the Spa in the village of Banya is of local significance.
* Since January 1st, 1999, Bulgaria has been divided into 28 administrative districts, called 'oblasts'. They are further subdivided into 264 municipalities.