Upper Idrijca landscape park is an area of solitary trails, deep gorges, lush forests, and unique technical heritage. This diverse landscape formed by the Idrijca and Belca rivers with their tributaries features gorges, geological faults, numerous waterfalls, beautiful natural pools, and springs. Colourful rocks of various composition, hardness, age, colour, and shape show us evidence of life in the distant past. In permeable rocks, karst phenomena were formed, but magma rocks can also be found and they indicate volcanic activity in the distant past.
This variety together with a mixture of Mediterranean and Alpine climates contributes to the diverse flora and fauna. The steep slopes above the Idrijca and Belca rivers are covered with forests that used to serve as important raw material and energy source for the operation of the mine. Today, they have an economic, ecological and preservation role.
The Idrijca River flows from Mrzla Rupa at the edge of the Vojsko Plateau. It is one of the cleanest Slovenian rivers and very popular with fishermen.