an intermontane tectonic basin in Bulgaria. Length, 94 km; average width, about 10 km; area, about 780 sq km; average elevation, 350 m.
The basin is bounded on the north by the slopes of the StaraPlanina (Balkan Mountains) and on the south by the slopes of the Sredna Gora Range. The bottom of the valley is flat; in theeast it is hilly. It is bisected by the Tundzha River, a tributaryof the Maritsa. The climate is warm temperate, with Januarytemperatures of 0° to — 2°C and July temperatures of about20°C; annual precipitation is about 600 mm. The basin has plan-tations of Kazanluk roses and other essential-oil crops, land sownin grains, fruit plantations, and vineyards. The G. DimitrovReservoir and a hydroelectric power plant are also located in the basin.