Provalija Cave is about 500 m from the main road Nevesinje - Gacko. It can be reached through the bed of the Surdup stream. Because of its value, the Provalija Cave was placed under the protection of the state as a natural monument in 1954, by the decision of the National Institute for the Protection of Cultural Monuments and Natural Rarities.
In addition to the name Provalija, it is also popularly known as Little Windmill. The cave itself was once one of the sources of the Surdup stream, and even today the bigren tubs in the cave are filled with water even in the driest period of the year. With 4,100 m of channels measured and drawn so far, the cave has taken the fourth place in length in Bosnia and Herzegovina. According to the configuration of the terrain and the direction of the channel, it has a huge potential for further research.
It is very important to mention that the beauty of the cave jewelry in Provalija is among the most beautiful in the former Yugoslavia. Extremely rare forms of cave jewelry were found here: helectites and cave pearls.