limestone cave in postojna

adelsberg adelsberger age ancient area attraction cave caves deposition depositions excavate excavates grotto huge imposing imposingly impress impressively layers lime limestone limestones mattock nature nicely noteworthly old pivka postojna pronged railway reserve river road rogue sandstones slovenia slovenian spectacle stalactite stalactites stalagmit stalagmiten stone stones system tourism tourist two verkalt visitor waters way yugoslavia