crevice-type cave, pseudokarst, slope movements, flysch, Outer Western Carpathians

The Cyrilka cave (the Moravskoslezské Beskydy Mts., Outer Western Carpathians) with the length of 535 m is the longest crevice-type cave in Czechia. The cave has typically developed passages within the sedimentary flysch rocks - sandstones, conglomerates and claystones, siltstones. The whole cave complex is formed in the upper part of vast landslide ant it is predisposed by three types of discontinuities: bedding planes, faults and joints. The cave complex represents an exceptional example of well-developed underground spaces within progressively evolving headscarp area of deep-seated landslide in sedimentary flysch rocks. The cave passages have specific morphology. Currently, the geomorphological and also the biological research have been performed within the cave system in order to prepare the groundwork for natural monument declaration.