The Trigrad Cave , also called the Devil’s Throat Cave (Dyavolskoto Gurlo Peshtera) has extensive and speleologically significant grottoes. The mandatory, 20-minute guided tour requires three or four tourists; you can stay longer, under the caretaker’s supervision. As you descend, you can hear (but unfortunately not see) a 45m-high waterfall. Exiting involves a somewhat daunting set of steep steps. You may see a (harmless) bat or two flitting about.
