The geological site “Il Fungo di Arzachena” (in Sardinian Monti incappiddatu, i.e. mountain with a hat), symbol of Arzachena's identity, owes its name to its big mushroom-shape to which this natural sculpture symbolically reminds. It is forged in the granite rocks, typical of the whole territory of Arzachena. The chemical and physical processes of natural elements such as, water and wind, as well as the sea spray, has shaped over millions of years, the granite in such a way as to create the characteristic shape of a mushroom, complete with stem and hat. This stunning erosion is known as “tafone”. Archaeological excavations undertaken about fifty years ago, have highlighted, that the site has Neolithic origins, when it was used as a shelter. Nowadays, this geological site is just few steps from the inhabited center.