Planinska jama – Pivka branch sump
Planinska jama is the resurgence where the underground Pivka and Rak rivers meet before emerging as the Unica. The Pivka branch ends in a sump: the first diving attempt was made in January 1964 in 5 °C water with simple 5 mm wetsuits, and later explorer Tomo Vrhovec recorded the through-sump as 445 m long and deeper than 50 m for most of its length. Around 1.5 km of flooded passage (air distance) towards Pivka jama remains unexplored. The connection with the Postojna system is the long-standing goal of Slovenian cave divers.
Facts
- Region: Slovenia – Lakes, Rivers & Caves
- Area: Notranjska & Brkini (Cerknica, Postojna, Pivka)
- Depth: 0–50 m
- Level: advanced
- Current: moderate
- Type: cave
- Coordinates: 45.82080556, 14.24648889
- Highlights: confluence of the underground Pivka and Rak rivers, Pivka branch sump: start 16 m deep, through-sump 445 m long, deeper than 50 m along most of its length, first diving excursion January 1964 (water ~5 °C), unexplored ~1.5 km (air distance) towards Pivka jama, cave water 8–10 °C
- Permit: Tours are run by Jamarsko društvo Planina (Planina caving club); under ZVPJ the custodian/operator must be notified in advance. 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/
- Tips: Research-only, not available to visiting divers. The front part of the cave can be visited on tours run by the local caving club; the freely accessible part ends at an iron gate and the sumps are beyond it. Deep, cold, long sump with poor visibility.