Rodopi Mountains

The Rodopi (Bulgarian: Родопи, Rodopi, usually used with a definite article — Родопите, Rodopite, sometimes also called Родопа, Rodopa or Родопа планина, Rodopa planina; Greek: Ροδόπη, Rodopi, "red aspect") are a mountain range in Southeastern Europe, with over 83% of its area in southern Bulgaria and the remainder in Greece. Its highest peak, Golyam Perelik (2,191 m), is the seventh highest Bulgarian mountain. The region is particularly notable for the Karst areas with their deep river gorges, large caves and specific sculptured forms, such as the Trigrad Gorge.
http://en.wikipedia.org/wiki/Rhodopes