The only place where obsidian is known to be found in Sardinia in a natural state is the Punta Trebina, a mountain south-east of Oristano.
The Punta del Nasone, the highest point of Somma, is 3714 ft.
The public buildings include the cathedral (1760), the government palace, the municipal palace, the episcopal palace, the church of Santa Ana, a national theatre, a school of arts and trades, a foreign hospital, the former administration building of the Canal Company, Santo Tomas Hospital, the pesthouse of Punta Mala and various asylums. The houses are mostly of stone, with red tile roofs, two or three storeys high, built in the Spanish style around central patios, or courts, and with balconies projecting far over the narrow streets; in such houses the lowest floor is often rented to a poorer family.
Callao is the principal port of the republic, its harbour being a large bay sheltered by a tongue of land on the south called La Punta, and by the islands of San Lorenzo and Fronton.
The hill of Dascon is to be sought a trifle to the south-east, to the south of the mouth of the Anapus, on the edge of the Great Harbour, at the Punta Caderini.