Škocjanske jame – Reka sumps (Ledeni dihnik, Marchesetti lake)
The Reka river disappears into the Škocjan Caves and flows through a giant underground canyon to terminal sumps. Slovenian divers passed the Ledeni dihnik siphon around 1990 and found more than 200 m of new passage, and in 1991 Janko Brajnik and Samo Morel swam through the siphon in Marchesetti lake just before Dead Lake, finding large passages with a river and lakes. Current exploration aims to link the system with Kačna jama about a kilometre away. In December 2025 a 49-year-old Slovenian diver died in the roughly 200 m long, 20 m deep Ledeni dihnik siphon in Martel's Hall during a research dive; recovery took 16 hours and over 100 rescuers.
Facts
- Region: Slovenia – Lakes, Rivers & Caves
- Area: Vipava valley & Karst (Škocjan)
- Depth: 0–21 m
- Level: advanced
- Current: strong
- Type: cave
- Coordinates: 45.6620663, 13.98448 (approximate)
- Highlights: underground Reka river canyon (UNESCO World Heritage), Ledeni dihnik siphon ~200 m long, ~20 m deep, >1 km from the entrance, 1991: Brajnik & Morel passed the Marchesetti lake siphon before Dead Lake, goal: connection to Kačna jama, rapids and boat transport to reach the sumps, fatal diving accident in December 2025 (bottom at 21 m)
- Permit: The cave lies in the Škocjan Caves Regional Park, managed by the public institute Park Škocjanske jame (Škocjan 2, 6215 Divača); under ZVPJ Art. 14 the park, as protected-area manager, 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: Park Škocjanske jame (public institute) – administration
- Phone: +38657082100
- Email: tajnistvo@psj.si
- Website: https://www.park-skocjanske-jame.si/
- Tips: Research-only, not available to visiting divers: the sumps lie far beyond the tourist route, reached only with boats across rapids by a caving team. Exploration is coordinated with the park; flood-prone river cave. Visitors can see the canyon only on the park's guided tours (no diving).