Medené Hámre Adit is located in Special Area of Conservation Homoľské Karpaty in the cadastral territory Borinka. The adit is stamped in limestone, it has 2 separate entrances and accessible corridors are 500 metres long. I tis very important wintering of bats. Since 1993 it is realized here monitoring of bats, which is realized by The basic organization of the Slovak Union of Nature and Landscape Miniopterus. Common pipistrelle (Pipistrellus pipistrellus) creates here the largest colonies and in 2006 wintered here over 600 individuals of Common pipistrelle. In the past it was discovered here rare species of common bent-wing bat (Miniopterus schreibersii).