Grotta del Cavallone is the show cave of the eastern Majella, reached from the Lama dei Peligni area. It is sometimes called the Grotta della Figlia di Jorio, a name linked to Gabriele d'Annunzio's play and the romantic mountain imagery of Abruzzo.
The approach is part of the appeal: you climb into a limestone world of cliffs, woods, and cool air before entering the cave. Opening times can be seasonal, so check locally rather than assuming it is available year-round.