Planina Cave (Planinska jama)

<p>Planina Cave is where Slovenia's most famous underground river comes back into the light. The Pivka, which vanishes at Postojna, runs on through the rock and reappears here, joining the equally hidden Rak in an underground confluence — a meeting of two subterranean rivers that is rare anywhere in the world, and the reason speleologists rate the cave so highly. The standard guided visit walks about 500 metres of secured path from the great arched entrance to that confluence; the boat passage deeper into the cave is a separate, far longer expedition.</p><p>Water tracing has shown the Planina and Postojna systems to be connected; together they form the Postojna–Planina Cave System, at least 34 kilometres of passage and, by the count of the biologists who work it, the most species-rich cave system in the world. The olm lives here too, in genuinely wild conditions rather than a vivarium.</p><p><strong>Planning your visit.</strong> Two very different visits share one entrance. The standard guided walk goes about 500 m along a secured path to the meeting of the Pivka and the Rak and takes one to two hours. The boat trip through the water passage is a 5–7 hour expedition, only possible by prior arrangement and only when water levels allow. Both are guided and neither is walk-in: fix the date and the tour with the guides ahead of time, and if you are attempting the boat, that is your whole day.</p>