Wild Lake
A small, still pool that sits on top of a flooded shaft at least 160 metres deep.
A lake with no bottom in sight
Divje jezero, a karst spring of the Vaucluse type.
Two kilometres south of Idrija, a small green lake lies at the foot of a rock wall about a hundred metres high. It is the top of a flooded cave. Water from the karst plateau of Črni Vrh rises through a steeply inclined passage and wells up into the pool. Divers have followed it down to about 160 metres without reaching the end.
In dry weather the surface is still and the lake looks harmless. After heavy rain it changes character within hours: the water surges up from the depths, the surface boils, and the outflow becomes a torrent. That is the reason for the name.
Wild Lake at a glance
- Slovene name
- Divje jezero
- Location
- 2 km south of Idrija
- Type
- karst spring over a flooded shaft
- Explored depth
- about 160 m
- Outflow
- Jezernica, about 55 m long
- Protected
- natural monument; open-air museum
- Entry
- free
- Swimming and diving
- not permitted without authorisation
Fifty-five metres to the Idrijca
The stream that leaves the lake, the Jezernica, joins the Idrijca river after only about 55 metres. It is usually cited as the shortest river in Slovenia.
A footpath circles the lake, with panels on its geology and on the plants of the cool, shaded cliffs, which include the Carniolan primrose, a species found only in Slovenia.
Beautiful and dangerous
The flooded passage has drawn cave divers since the 1950s, and several have died in it. The water is about 7 to 10 °C, visibility can collapse in minutes, and the depth requires mixed gases and long decompression. Diving is allowed only by special permission.
Olms live in the system and are occasionally washed up into the lake during floods.
Idrija, the mercury town
Idrija grew up around what was for centuries the second-largest mercury mine in the world. Together with Almadén in Spain it is a UNESCO World Heritage Site. Part of the mine, Anthony's Shaft, is open to visitors, and the town is also known for its lace and for žlikrofi, small potato-filled dumplings.
A level path, the Rake, follows an old water channel from the town to the lake in about half an hour.
Visiting Wild Lake
Getting there
Idrija is about an hour from Ljubljana by road. The lake is beside the road towards Ljubljana via Godovič, with a small car park, or half an hour on foot from the town along the Rake path.
How long
The circuit of the lake takes 20 minutes. Allow half a day if you add the mine and the town.
Good to know
Keep back from the edge when the water is high. The best time to see the spring in action is the day after prolonged rain.
