1) Mountain of Serbia 
Rtanj (pron) is a mountain situated in eastern Serbia, approximately 200 km southeast of Belgrade, between towns of Boljevac on north and Sokobanja on south. It belongs to the Serbian Carpathians. Its highest peak is Šiljak (pron) (1,565 m), a natural phenomenon of karst terrain. The north side of the mountain is covered with forests and shrubs, ...