The north-western portion of the island, called the Nurra, lies to the west of Sassari and to the north of Alghero, and is entirely volcanic; so are the mountains to the south of it, near the west coast; the highest point is the Monte Ferru (3448 ft.).
For some way beyond the only seaport is Bosa, which has only an open roadstead; and at the southern extremity of the Nurra come the Gulf of Alghero and the Porto Conte to the W., the latter a fine natural harbour but not easy of ingress or egress.
The northern extremity of the Nurra, the Capo del Falcone, is continued to .the N.N.E.
Xviii.; Nissardi's map of the Nurra, published by G.