Starosel is a village in central Bulgaria, Hisarya Municipality, Plovdiv Province. It lies at the foothills of the Sredna Gora mountain range along the shores of Pyasachnik river.

Sredna Gora is a mountain range in central Bulgaria, situated south of and parallel to the Balkan Mountains and extending from the river Iskar to the west and the elbow of river Tundzha north of the city of Yambol to the east. Sredna Gora is 285 km long, reaching 50 km at its greatest width. Its highest peak is Golyam Bogdan at 1,604 m (5,262 ft). It is part of the Srednogorie mountain chain system, which extends longitudinally across the most country from west to east, between the Balkan Mountains and the Sub-Balkan valleys to the north and the Kraishte, Rila and the Upper Thracian Plain to the south.