Pivka & Black Caves (Pivka jama & Črna jama)

<p>Pivka jama and Črna jama (the Black Cave) belong to the same great Postojna system but are shown in the opposite spirit: unlit, undeveloped and walked on foot. Pivka Cave runs a little over five kilometres and the Black Cave about 3.3; the two are joined by an artificial tunnel driven through the rock by the Italian military during the occupation that followed the First World War. A long stair descends a collapse doline to reach the entrance, and the tour follows the Pivka river through echoing, largely unadorned galleries.</p><p>These are the last caves in which the Pivka is visible before it disappears entirely, to surface again downstream in the Planina Cave. For anyone who found Postojna too polished, this is the same underworld with the handrails taken away — and the reason to come is the atmosphere rather than the decoration.</p><p><strong>Planning your visit.</strong> Guided access only, and the schedule for these two caves moves more than any other on this list — tours are seasonal, have been suspended in some recent seasons, and are partly folded into a summer trekking tour of the three caves. Check the official timetable and book before you set out rather than driving over on spec. Allow about an hour and a half for the tour itself, plus the stair descent and climb back.</p>