Situated at the bottom of Alburni Mountains la Grotta dell’Angelo (Angel Grotto) in Pertosa represents one of the major karst phenomena in Southern Italy, probably started 35 millions of years ago. The entrance is through a large cave which gives access to the many grottoes and narrow passages known as Pertosa Grottoes. The visit starts on board of a boat which, like in Charon’s crosses, allows to get to the other side of the underground river Nigro, to the entrance of the grottoes which are divided into different branches named: Sorgente (Fountain), Paradiso (Paradise) and Meraviglie (Wonders). The latter is undoubtedly the more suggestive of the three owing to the many stalactites and stalagmites variously shaped among which ‘the elephant’ and ‘the sphinx’ are only two representative examples worth mentioning. The visit ends through the Sponges Hall where, thanks to the particular limpidness of the rocks, it is possible to appreciate that natural prodigy even better.. An element which makes the visit more interesting and stimulating is the idea, which has been going on for some years, to stage Dante’s Hell inside the caves, which adds suggestion to the beauty of a natural scenery and, at the same time, gives tourists the chance to admire the place from other perspectives.