The Tacchi d’Ogliastra cover a large part of the Ogliastra territory. They are dolomitic limestone mountains whose name derives from the typical shape resembling the heel of a shoe. The most famous one of all is Perda Liana (Gairo). There are also the  Mount Tisiddu Tacco, the Arba di Ussassai Tacco, Mount Lumburau, Mount Arquerì, Taccu Anguil'e Ferru and Punta Corongiu at Jerzu. Other sites of outstanding beauty are the San Giorgio pass, near Osini, and the Su Marmuri caves (Ulassai). 
The geomorphology of this territory is characterised by vast outcrops of Paleozoic rocks, represented by Silurian schists, which form the crystalline base on which the Mesozoic limestone formations rest. The Tacchi let you visit some of the wildest and most unique places in Sardinia. There is a spectacular variety of flora and fauna of outstanding natural interest, with important species endemic to this area. The Tacchi area has many fascinating nuragic settlements, including Serbissi, Sanu, Urceni, Mela, Is Cocorronis, Pranu and Su Samuccu. The Tacchi area protects and preserves ancient agro-pastoral activities such as breeding, viticulture (Cannonau di Jerzu) and handicrafts.