Bulgaria - The Vratsa Karst

"It covers the greater part of the Vratsa Mountains which are a part of the West Balkan Range. It represents the biome of a mixed mountain system of a complex zoning of the Balkan biogeographical region characterized by the coexistence of relict and sub-Mediterranean types. It shows fine examples of geological processes which are of major scientific interest. The Vratsa Karst furnishes a striking illustration of the evolution of certain types of fauna. The Vratsa Karst incudes remarkably beautiful geomorphological formations and natural scenery, and all the Karst phenomena and forms: vortexes, hollows, Karst precipices and caverns. The most remarkable of the caves are Zmeiova doupka, the Ledenik, the Serapion Cave, impressive vertical layers from 60 to 200 meters high." Source: UNESCO World Heritage Tentative List

Map and multi-view of Natural Park Vrachanski Balkan, Vratsa. Thanks to Christina of Bulgaria.