Vjetrenica is the most famous cave in Bosnia and Herzegovina, a protected natural monument and a tourist destination in the southeastern part of Herzegovina. It is located 300 m east of Zavala in the municipality of Ravno, and 12 km from Slano on the coast of the Adriatic Sea (Croatia).

Vjetrenica is a hydrological active, speleological and drifty object with even four water streams, as well as more than ten further, smaller periodical water streams with subterranean lakes. Located in the southern side of the Dinara rock mass, with an access at the sole edge of the Popovo-field, 300 m to the East of the village’s centre called “Zavala” with an altitude of 260 m above sea level and an air-line distance of 12 km to the Adriatic Sea.

The underground habitats of Vjetrenica consist of cave channels, cracks, underground waters and other underground living spaces. The appearance of a strong “wind” at the entrance is a fascinating feature of the Windmill. Strictly speaking, it is not about the wind, but about the physical phenomenon of air flow, which aims to equalize the constant internal and variable external air temperature.