A temperate climate with cold winters, cool springs and mild summers hampers the agricultural use of the otherwise fertile mountain valleys. Stara Planina, Sredna Gora and Rila are the principal mountain ranges that the province straddles, while Plana and Vitosha lie entirely within its territory. The highest peak on the Balkan Peninsula, Musala, rises 2,925 metres above sea level in Rila at the southern end of the province.