The Ledena jama cave in Stojna
The Ledena jama cave is a Karst cave or chasm with permanent ice at the bottom. The ice is formed in special micro-climate conditions causing the water to freeze in winter time. While in summer it keeps low temperatures. (i.e. cold air clouds). The main source of ice is the underground water (rainwater) freezing in ice caves. If the ice surface is uncovered to the south and sometimes bathing in the sun, also the forest helps to preserve low temperatures.
In the Slovenian climate conditions the ice caves can be found at the altitudes around 1000 m. Only 10 % of 150 ice caves can be found at the lower altitudes. The most famous is the Ledena jama cave in Stojna which is originally registered in the cadastre under the name Ledena jama v Fridrihštajnskem gozdu.
The entrance to the cave lies at the altitude of 870 m. The northern wall is completely vertical or precipitous, while the less steep channel in the south offers an access point. Since the cave is extremely open from the south the sun reaches deep, causing the ice to remain only at the depth of 50 m. There is a 20 x 30 m large ice formation also called the “ice lake” representing the peak of the ice structure and is full of icy ornaments in the spring time. Ice cascades hang from the wall crevices long into the spring time. Due to the ice melting at the wall complex, the cave continues deep down along the eastern and western crevice – the speleologists have managed to reach the depth of 105 m below the entrance between the ice and rocky wall along the western rift through the chamber in between. The quantity of ice is estimated to 30,000 m3 and is quickly decreasing due to climate changes (atmospheric warming, distribution of precipitation, less snowy days). The Ledena jama cave was a tourist destination and a natural refrigerator in the past. Due to the increasing ice melting (5 m in last 20 years) the wooden infrastructure is destroyed, while the access to the ice lake is very difficult without proper technical equipment. Due to global climate changes, the ice melting is expected to continue.
The Ledena jama cave in Stojna is registered also in The inventory of the most significant natural heritage of Slovenia, the book Sto naravnih znamenitosti Slovenije and other literature.
Already in the first forest management plan of 1892 prohibits the felling of trees in the vicinity of the Ledena jama cave. Today, it is protected as the Ledena jama cave forest reserve. The forest reserve lies on the Stojna plateau, southwest to Mestni vrh, in the forest sector 69 c. It includes fir-beech forests covering 14.79 ha. 2.00 ha of forest surrounding the cave were excluded from the forest management by the Decision of the Assembly of the Municipality of Kočevje of 1976. In 1993, the foresters expanded the reserve area with the purpose to conserve climate conditions preventing the further process of ice melting in the cave and to protect natural features such as Kraljevi studenec stream, walls, and Karst caves.