Postojna Cave

A karst cave system 24.34 kilometres long, cut by the Pivka, and the second longest in Slovenia after the Migovec System. Valvasor described it in the seventeenth century, though graffiti dated 1213 shows much earlier use. In 1818, while the cave was being prepared for a visit by Emperor Francis I, a local lamplighter named Luka Čeč stumbled on a whole new section; when the cave opened to the public he became its first official guide. Adolf Schmidl’s survey in the 1850s became a standard reference in speleology.