Hungary – Caves & Mines

Hungary has no sea, but its karst hides some of Central Europe's most unusual overhead diving. Right in Budapest, the thermal Molnár János Cave runs for kilometres under the Buda hills, and the flooded quarry tunnels and brewery cellars of Kőbánya can be dived on guided trips. In the Balaton Uplands the spring caves of Tapolca and Hévíz, and in the north the cold karst springs of the Bükk and Aggtelek, are open only to small, permitted groups. Every cave in Hungary is protected by law: cave diving needs the consent of the national park directorate and a qualified cave dive leader, and some caves can be entered only by research teams. Former mines and quarries are usually private land, so the owner's permission comes first.

Facts

• Caves are protected by law: Under the Nature Conservation Act (Act LIII of 1996, §23(2)–(3)) every cave – a natural cavity longer than 2 m that a person can enter – is protected by force of law, without separate designation; protection covers the entrance, passages, formations, fill and cave fauna (§48). All caves are exclusively state-owned and the national park directorates are their custodians (§68). (source: njt.jog.gov.hu)
• Cave diving needs national park consent: Cave diving, like cave research, filming and visiting certain caves, requires the custodian's consent (vagyonkezelői hozzájárulás) from the competent national park directorate (Nature Conservation Act §51(4)). Using or developing a cave needs a separate permit from the minister (§51(1)). (source: njt.jog.gov.hu)
• Decree on cave visits and diving: Decree 17/2021 (IV.9.) AM sets the details: consent is issued only for a specific date, the directorate decides within 15 days, divers dive at their own risk and the dive leader is responsible for compliance. The application must include the dive leader's details and certificate numbers, site, purpose, route, timing and number of divers. (source: njt.jog.gov.hu)
• Caves open to non-research diving: Annex 4 of Decree 17/2021 lists: Molnár János-barlang (Duna–Ipoly NP, max 50/day); Baradla Rövid-Alsó-barlang first closed sump No. 4 (Aggtelek NP, 10/day); Szalajka-forrásbarlang (Bükk NP, 5×2/day); Halász Árpád-barlang (2×2/day), Hévízi-forrásbarlang (20/day), Tapolca cave system – Kórház-barlang part (4/day) and Tavasbarlang part (20/day) (all Balaton-felvidéki NP). Any other cave can be dived only under a research permit. (source: njt.jog.gov.hu)
• Required dive-leader qualification: For cave-visit dives the dive leader must hold the Hungarian Diving Federation (MBSZ) cave dive-leader qualification plus 'cave diver III' (barlangi búvár III.) or an equivalent international certification; for training dives 'cave diver instructor II' plus 'cave diver III'. Diving research requires 'cave diver instructor trainer' or equivalent. Individual participants need cave certification matching the dive (the Molnár János operator asks for at least Cave Diver Intro level for guided cave dives). (source: njt.jog.gov.hu)
• Research permits: Cave research (including exploration diving) needs a research permit valid for up to 3 years, decided within 60 days (Decree 17/2021 §7). In recent practice these procedures have been run by the county government offices' environmental and nature-protection departments, e.g. the Pest County Government Office for the Molnár János-barlang (2016) and the Zala County Government Office for the Hévízi-forrásbarlang (2026). Check the competent authority currently. (source: termeszetvedelem.hu)
• Molnár János Cave water temperature: The upper flooded level is warmed by thermal springs to about 28 °C; below a thermocline at around 10 m the water is about 18–20 °C, so deeper penetration needs a drysuit or thick wetsuit. Other sources give 20–23 °C or 25 °C overall. (source: divernet.com)
• Molnár János Cave visibility: The water is described as crystal clear, but very fine sediment near walls and floor can cause a rapid silt-out; slow spring flow helps it clear. No numeric visibility figure is published. (source: divernet.com)
• Cave rescue: Cave accidents are handled by the Hungarian Cave Rescue Service (Magyar Barlangi Mentőszolgálat) with its regional units, together with disaster-management and police units; underwater recovery is done by specialist cave divers (e.g. the 2022 Kossuth-barlang recovery, coordinated by TEK with Amphora cave divers). In an emergency call 112. (source: hvg.hu)
• Fees and opening: Dive prices, booking rules and opening days of the Molnár János Cave dive center change from year to year (latest price list found: valid from 5 Feb 2025; office hours 8:00–16:00 depending on bookings). Check current information before travelling. (source: mjcave.hu)
• Kőbánya cellars – certification: Park-kút (open air space above) can be dived by OWD/AOWD on guided dives; the other wells need cave or wreck-penetration (overhead) training and doubles; one operator requires 100+ dives. (source: titanbuvar.hu)
• Pit lakes – swimming bans and fines: Where a no-swimming sign is posted, entering the water (also with floats) is banned; on-the-spot fine 5,000–50,000 HUF, up to 150,000 HUF in proceedings (archived Pest County police notice – check current amounts). (source: ocsa.hu)
• Pit lakes – hazards: Pit lakes deepen abruptly (10 m a few steps from shore), only the surface warms up, and submerged objects may lie on the bottom. (source: ocsa.hu)
• Mining Act: Mining and mine safety in Hungary are governed by Act XLVIII of 1993; most former pit lakes and quarries are private property, so the owner's/operator's consent is needed to enter. (source: fgsz.hu)
• Emergency: Call 112. For diving accidents, DAN Europe members can also call the DAN Europe international hotline (+39 06 4211 5685 – check the number on your card). (source: daneurope.org)
• Recompression chamber: The Hyperbaric Oxygen Therapy Centre of Vaszary Kolos Hospital, Esztergom (Petőfi Sándor u. 26-28, +36 33 542 387) describes itself as Hungary's only hospital hyperbaric centre and lists diving accidents (DCI) and gas embolism as urgent indications. 24/7 availability is not stated – check current status. (source: vaszary.hu)

Season

• Best months: Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec
• Water temperature: 20–25 °C

Caves and mines can be dived year-round. The Molnár János cave in Budapest is thermal at about 20–25 C; dives need a permit and rules tightened after a 2011 fatality. Karst caves turn turbid after heavy rain. No exact temperature source was found.

Dive sites (9)

North Hungarian Mountains

• Baradla Rövid-Alsó-barlang – advanced
• Kossuth-barlang – 0–48 m, advanced
• Rudabányai bányató – 0–36 m, advanced
• Szalajka-forrásbarlang – 0–55 m, advanced

Balaton Uplands & Bakony

• Halász Árpád-barlang – advanced
• Hévízi-forrásbarlang – 38–40 m, advanced
• Tapolcai-tavasbarlang – 0–10 m, advanced

Budapest

• Kőbányai pincerendszer – 0–36 m, advanced
• Molnár János-barlang – 0–100 m, advanced

Operators (4)

• MJ Cave – Molnár János Cave Diving Center – dive centre, 1023 Budapest, Frankel Leó utca 48.
• Titán Búvár Iskola – dive centre, 1118 Budapest, Kelenhegyi út 12-14.
• Búvár-ABC – dive centre, 1188 Budapest, Szövet u. 9.
• BornToDive – dive centre, Budapest

Cave and mine diving is overhead diving: without cave training, the right gas planning and a guideline it can be fatal. Every site here needs a permit or an organised dive; rules, quotas and prices change, so check them with the national park directorate, the owner or the operator before you go. Positions are for orientation only.