Also called 'Devil’s Throat Cave', this dank cave system was burrowed out by the Trigrad River over millennia. A mandatory 20-minute guided tour, requiring three or four tourists, leads you into grottoes with dangling stalactites. As you descend into the cave, you can hear a 42m-high waterfall. Exiting involves a daunting set of steep steps. You can stay longer under the caretaker’s supervision. You'll need private transport to reach the cave, 2km north of Trigrad village via a narrow mountain road. It's a 25km drive south of Devin.