Divje Jezero

Divje jezero, the wild lake, is a small green pool at the foot of a cliff south of Idrija, and it is the visible top of a flooded shaft that divers have followed downwards past a hundred and sixty metres without finding the bottom, which makes it one of the deepest explored siphons in Europe. It was declared a natural monument in 1967 and in 1972 became Slovenia's first museum in nature. The shaft has been followed for 415 metres, and in flood the discharge can pass sixty cubic metres a second. Out of it runs the Jezernica, about fifty metres long, regularly called the shortest river in the country.

The landscape

• The pool - a small green surface over a flooded shaft of unknown depth.
• The Jezernica - a river some fifty metres long running from the pool to the Idrijca.
• The overflow - the spring erupting in flood after heavy rain, when the flow multiplies.
• The museum in nature - Slovenia's first, laid out here in 1972.

When to go

Year round; after heavy rain or snowmelt the spring overflows dramatically, which is the best time to see it working. In drought the pool is still and low. The path is short and open all year.

Practical notes

It is a small pool and a five-minute walk, and outside flood conditions there is not much happening. Diving in the shaft is restricted. Swimming is forbidden.

Nearby

Idrija and its mercury mine are north, and the Idrijca valley runs south.

Key facts