Information for Tourists: Wild Lake

One of the pearls of Slovenia’s natural heritage is located two kilometres south of Idrija, Obalno Kraška region. The mysterious karst Wild Lake (Slovene: Divje jezero) is a true natural monument and the first Slovenian open-air museum.

“Where the river is deepest, it makes least noise,” the Slovenian proverb says. During the rain, the usually calm, emerald surface of the lake turns into a real wild water miracle. The lake is hidden in the rocky terrain of the Črni Vrh Plateau having several hundred metres in height and communicates with mysterious underground currents. The lake gives origin to a small river Jezernica, which, being the shortest river in Slovenia, joins another river, Idrijca, right after the next 55 metres. The water temperature in the lake is at a level of 7–10°C. In summer, its surface can warm up to 20°C.

The Wild Lake and its surroundings have rich flora and fauna. Many indigenous plants have survived the last ice age. Rare alpine flowers and herbs grow on rocks and their ledges above the lake – for example, Carniolan primrose, an endemic plant known for over 200 years. Brook trout lives in the lake and in the nearby cave there are many tiny underground animals and even the olm, or blind white salamander, familiar to tourists by the Postojna cave.

The Wild Lake is a karst siphon lake. This means that it has an underground influx. This type of karst source is characterised by pressure, which causes water to flow from depths to the surface through steep channels. The gorge, through which water flows into the Wild Lake, is extremely steep and explored only to a depth of 160 metres. Its area is 0.23 hectare.

Thanks to all of the above facts, in 1967, the Wild Lake with its surroundings received the status of a natural monument. In 1972, a corresponding infrastructure was developed for tourism purposes, such as the first Slovenian open-air museum. Besides, in 1993, the lake became part of the Zgornja Idrijca Landscape Park.