The
Upper Thracian Plain (,
Gornotrakiyska nizina) constitutes the northern part of the historical region of
Thrace. It is located in southern
Bulgaria, between the
Sredna Gora mountains to the north and west; the
Rhodopes,
Sakar and
Strandzha to the south; and the
Black Sea to the east. A fertile agricultural region, the Upper Thracian Plain proper has an area of and an average elevation of . The plain is part of
Northern Thrace (Северна Тракия,
Severna Trakiya). The climate is transitional continental. The highest temperature recorded in Bulgaria occurred here: it was at
Sadovo in 1916. The precipitation is a year. Important rivers are the
Maritsa and its tributaries, the
Tundzha, the
Stryama, the
Topolnitsa, and the
Vacha.