The great gypsum karst of the Western Ukraine, which is associated with Miocene (Badenian) gypsum, provides the worlds foremost examples of intrastratal gypsum karst and speleogenesis under artesian conditions. Differential neotectonic movements have resulted in various parts of the territory displaying different types (stages) of intrastratal karst, from deep-seated, through subjacent, to entrenched. Internal gypsum karstification proceeded mainly under confined hydrogeological conditions. While such development still continues in part of the territory, other parts exhibit entrenched karst settings. Huge relict maze cave systems have been explored here, five of which are currently the longest known gypsum caves in the world. They account for well over half of the total length of gypsum cave that has been explored. This unique concentration of large caves reflects the local coincidence of specific structural prerequisites of speleogenesis (character and extent of fissuring), favourable regional evolution (rapid uplift, and fossilization of maze systems), the presence of overlying limestone aquifers, and a widespread clayey protective cover (which prevented the total infilling and/or destruction of the caves). Surface karst evolved as a consequence of the internal karstification in the gypsum, and the karst landform assemblages differ between the territories that present different types of karst.