The mild and uniform temperature (15 degrees) makes pretty this route of 280 steps that arrives until the base of the Guinnes column (38 metres high), that joins the floor with the ceiling. Among the other peculiarities the Virgins abyss, a deep and tight funnel that connects the underground with the underground branches, and set in for 12 km in earth viscera. At the base of the abyss Phoenician jewellery made by vitreous paste (exhibited at the archaeological museum of Dorgali) and bones attributed to young women. Because of this finds a legend was born: here Phoenician made human offerings to ingratiate divinities.