The Grotto of Sibylla, also called the Grotto of Alcina or of the Fairies, is a cavity located at a height of 2,150 m on the face of Mount Sibylla. Undoubtedly inhabited as far back as prehistoric times, according to the legend it housed a prophetess condemned by God to live in the depth of the mountains until Judgement Day, because she wanted to become the mother of Christ.
Local tradition instead identifies Sibylla as the “Fairy Sibylla”, a good fairy whose handmaidens every so often went down to the valley to teach the art of spinning and weaving to local girls. Abramo Oertel (1527-98) (Cordella and Lollini, 1988) tells of the grotto being a horrible cavern providing access to a kingdom full of comforts and refined young girls, where the enchantress Alcina also lived.
The present appearance of the cavity certainly conflicts with the suggestive and fascinating descriptions given in the various stories. It is inaccessible because of clumsy attempts made to widen the opening using explosives.