Rtanj is a mountain situated in eastern Serbia, approximately 200 km southeast of Belgrade, between the towns of Boljevac on north and Sokobanja on the south. It belongs to the Serbian Carpathians. Its highest peak is Šiljak, a natural phenomenon of karst terrain. ()
Local name: РтањElevation: 5135 ftCoordinates: 43°46'34"N, 21°53'36"E