Lukenjska jama (cave below Luknja castle) – sump
A periodic spring cave in the Luknja pocket valley near Prečna, where the Temenica resurfaces. A siphon lake between the passage and the inner hall spews water in rain and floods the cave. Divers explored the sump in 1997: after almost 50 m it led into a beautifully decorated passage that ends after 100 m in another sump lake. The cave is also a Palaeolithic site and an important bat refuge.
Facts
- Region: Slovenia – Lakes, Rivers & Caves
- Area: Dolenjska & Bela krajina (Krka, Kolpa, Kočevje)
- Level: advanced
- Current: moderate
- Type: cave
- Coordinates: 45.8184596, 15.0997182 (approximate)
- Highlights: periodic spring cave at the Temenica resurgence, siphon lake floods the cave in rain, sump explored by divers in 1997, ~50 m sump into a richly decorated passage, next sump lake after 100 m, Palaeolithic site; bat refuge (Natura 2000), endemic amphipod Niphargus stenopus
- Permit: Also an archaeological site and Natura 2000 area (cultural-heritage rules apply to archaeological remains, ZVPJ Art. 7). Under the Cave Protection Act (ZVPJ) every cave, including water-filled ones, is state-owned and protected. Only persons certified for independent caving (certificate checked by the Speleological Association of Slovenia, JZS) may explore caves, and they must notify the cave's custodian, concessionaire or protected-area manager in advance (Art. 14); closed caves can be entered only for scientific/archaeological work with a permit from the ministry responsible for nature conservation (Art. 17). There is no visitor dive permit: in practice diving here happens only as a member of the caving/cave-diving team that runs the exploration.
- Issuer / contact: Ministry of Environment and Spatial Planning – Nature Conservation Sector
- Phone: +38614787335
- Email: gp.mop@gov.si
- Website: https://www.gov.si/teme/podzemne-jame/
- Unverified: Only one source (club cave sheet) describes the 1997 dive; sump depth not given.
- Tips: Research-only, not available to visiting divers. Archaeological and Natura 2000 bat site – do not disturb sediments or bats. The open-water Temenica pools below the fish farm are a separate (non-cave) dive site.