Wild Lake

An excellent 3km trail called Pot ob Rakah follows the Idrijca River Canal from the Kamšt to Wild Lake, a tiny, impossibly green lake fed by a karst spring more than 80m under the surface. After a heavy rainfall, water gushes up from the tunnel like a geyser and the lake appears to be boiling (although the surface temperature never exceeds 10°C).

Wild lake was declared a natural monument in 1967, and little signboards around the shore identify the plants and trees and point out the lake's unique features. The body of water flowing from Wild Lake into the Idrijca just happens to be the shortest river in Slovenia. The Jezernica River is a mere 55m long.

If you were to follow the canal for 15km to the southwest, you'd come to the first of the barriers (klauže) of stacked wood and stones that dammed the Idrijca and Belca Rivers to float timber in the 18th century. They were once called 'Slovenian pyramids' because of their appearance. Wood was an important resource here, both to support the 700km of mine shafts and because the heat needed to extract mercury from cinnabar required a lot of fuel. The dams continue for 12km down the Belca River.