Karsts areas are “landscapes of special geological and geomorphologic interest which call for conservation” and can therefore be defined as potential geosites according to the definition given by Cleal et al. 2. This communication briefly describes the geological, geomorphologic and hydrogeologic features of the most important areas in North-Eastern Italy where highly karstified – both on the surface and underground – carbonate rocks outcrop. Some of them perfectly exemplify geological and geomorphologic events and their own geological history, thus serving as cultural models not only at a local but also at a global level 1. Typical examples of karst geosites are the Alpine Karst environment ofMt Canin and the Classical Karst near Trieste, as well as the Cansiglio – Cavallo Plateau, the limestone turbidites of Julian Prealps Flysch, the glaciokarst valleys of the Carnic Alps and the karren of the Devonian limestone.