Situated between the Serbian border and the city of Sofia, Dragoman Marsh Karst Complex is the only limestone marsh in Bulgaria, and one of the biggest of the Balkan Peninsula. A unique variety of wetland types is found in the Complex: it contains karst marshes, wet meadows, peatlands, human-made lakes and fishponds. Because of this variety, the Site is biodiverse, hosting 256 bird species, 9 reptiles, 23 mammals and 180 vascular plant species. The bird species represent 61% of all those found in Bulgaria. From the 1930s onwards, the wetland was almost completely drained, including through the construction of channels and pumping stations. However in the 1990s these activities ceased and the Site started to be quickly restored, remarkably regaining most of the species that had abandoned its habitats. Despite this recovery, discharge of untreated wastewater, quarrying activities and land conversion still represent significant threats.