The Devetashka cave is located 17 km northeast of the town of Lovech and 2 kilometers from the Devetaki village (itinerary Devetaki village), which is named after the cave. The cave is known as Maarata or Oknata for seven different-sized holes in the ceiling through which light penetrates and illuminates the central hall and part of the two branches.
First described in 1877 by English explorer James Baker, the cave was first explored in 1921 by Gabriel Katzarov who found clues of material culture. It made discoveries of some of the most interesting remains from the Neolithic period on Bulgarian lands. The earliest traces of human presence are from the middle of Old Stone Age about 70,000 BC.
The entrance to the cave is 35 meters wide and 30 meters high. At about 40 meters inside the entrance expands, forming a spacious hall with an area of 20,400 square meters. The height of the hall is 60 meters and the length of the entire cave is 2442 meters. The volume of the hall is 643,000 square meters, making it the largest in the Balkans. The maximum ceiling height is at the opening Kosherishteto - 58 meters, as Kilikat is the largest opening in size of 73 to 48 meters and height of 51 meters.
From the central hall about 200m from the entrance the Devetashka cave separates to two branches. The left is long over 2km, as it takes place in a small river which passes through the central hall and into the Osam river. The right branch is dry and warm. The entrance has a height of 2.5 meters and a width of 5.7 meters. Inside it expands and forms a rectangular hall 48 meters long and 14 meters wide. This branch ends in a small gallery with a round room, known by the name Altar.
In addition to archaeological finds, the cave is known for its diversity of residents. There live 12 species of protected amphibians, 82 species of birds that are found in the area, 13 of which were listed in the Red Book, 34 species of mammals (4 of which are included in the Red Book of Bulgaria and 15 in the global red list) and 9 species of bats.
The Devetashka cave is of international importance as a refuge for bats and is included as a priority item in the list of the Agreement on the Conservation of European bats EUROBATS.
Because the breeding season of animals inhabiting, the cave was introduced access control in both galleries of the cave. Water gallery is closed to visitors during the period 1 November to 1 April, and the dry gallery in the period 25 May to 31 July. The bright part of the cave is open to visitors year round.
The Devetashka cave was a secret military base until early 90s and was used for storage of oil and food from state reserves, with large oil tanks stood near the entrance of the cave. Until 2015, the oil tanks are removed as only part of pedestals reminds that.
In 2011, at Devetashka cave were shoot some scenes of the film The Expendables 2, which includes most of the major Hollywood action stars like Bruce Willis, Jason Statham, Sylvester Stallone, Dolph Lundgren, Arnold Schwarzenegger, Jet Li, Jean -Klod Van Damme and Chuck Norris. For the purposes of filming, the team film built a real bridge over the river Osam, who subsequently left as a gift to local residents.
Devetashka cave was declared a natural landmark by Order №.RD238 of 07.06.1996.
