Seven areas, in the provinces of Reggio Emilia, Bologna, Rimini, and Ravenna, compose the natural site called “Karst phenomena and Caves in the Evaporites of the Northern Apennines”. These are officially recognised as of universal value for their unique and representative features of the Earth’s geological and geomorphological evolution. Two of these areas lie in the hills outside Bologna. To the east, we find the largest one, that of the Gessi della Croara (with the well-known Grotta della Spipola) and between Zena and Idice (where we can find Grotta del Farneto), in the Gessi Bolognesi Regional Park, between the municipalities of San Lazzaro di Savena and Pianoro. To the west, we find instead the Gessi di Zola Predosa, in the municipality bearing the same name, which includes Grotta Gortani and falls within the Natura 2000 site Gessi di Monte Rocca.