The characteristic shape of the entrance to this karst cave, which resembles a lock or the hilt of a sword, has given rise to various legends. The most famous is linked to the passage of the Huns led by Attila through these areas. The treasure of the heathen leader (which has never been found) is alleged to have been hidden here. The cavity, crossed by the stream that collects the waters of the peat bog, consists of a tunnel almost 500 metres long.