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, the first in Slovenia. Out of it runs the Jezernica, about fifty metres long, regularly called the shortest river in the country.

What you actually see

• 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 1967 designation - the first natural monument declared in Slovenia.

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.

Honest expectations

It is a small pool and a five-minute walk, and outside flood conditions there is not much happening. Several divers have died exploring the shaft and diving is now restricted. Swimming is forbidden.

Nearby

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