Northern Thrace or North Thrace (Bulgarian: Северна Тракия, Severna Trakiya as opposed to Western Thrace and East Thrace to the south; Turkish: Kuzey Trakya; Greek: Βόρεια Θράκη), also called Bulgarian Thrace, constitutes the northern and largest part of the historical region of Thrace. It is located in Southern Bulgaria and includes the territory south of the Balkan Mountains and east of the Mesta River, bordering Greece and Turkey in the south and the Black Sea in the east. It encompasses Sredna Gora, the Upper Thracian Plain and 90% of the Rhodopes. The climate ranges from continental to transitional continental and mountainous. The highest temperature recorded in Bulgaria occurred here: it was 45.2 °C (113.4 °F; 318.3 K) at Sadovo in 1916. The main rivers of the region are the Maritsa and its tributaries. Notable cities include Plovdiv, Burgas, Stara Zagora, Sliven, Haskovo, Yambol, Pazardzhik, Asenovgrad, Kardzhali, Dimitrovgrad, Kazanlak and Smolyan. Northern Thrace has an area of 42,073 km².