The most biologically diverse single cave in the world: over 250 species recorded, including the largest known number of strictly cave-adapted (troglobite) species of any cave system. Among them are the blind cave fish (Salaria sceptella), several endemic cave shrimps, and the curious cave-dwelling olm — a pale, long-lived amphibian found only in this part of the Dinaric karst.
The visitor section is about 1km of fully lit, level walkway through huge chambers with stalactites, stalagmites, columns and the trademark Vjetrenica draught. Guided tours run several times daily in summer, less frequently in winter; the cave is in Ravno municipality, about an hour's drive west of Trebinje. Modest entrance fee, includes the guide. Wear warm clothing — the cave is around 11°C year round.