Mšenské vowicky is a rock formation located above Kokořínský mine in the nature reserve of the same name, at the mouth of a ravine called Močidla, between the settlement of Vojtěchov and the solitude of Hlučov. The upper slabs – lids – are made of ferruginous coarse-grained sandstones to conglomerates, in places over a meter thick, which cover irregular truncated cones of softer sandstones joined by kaolinic cement.
There are also formations in the vicinity that do not yet resemble lids very much, but represent so-called embryonic forms from which lids will develop over time, while today´s lids have completely succumbed to erosion and their top plates collapse.