Cagliari is the capital of the island of Sardinia, a region of Italy. Cagliari's Sardinian name Casteddu literally means castle. It has about 160,000 inhabitants, or about 400,000 including the outlying townships (metropolitan area): Elmas, Assemini, Capoterra, Selargius, Sestu, Monserrato, Quartucciu, Quartu Sant'Elena.

An ancient city with a long history, Cagliari has seen the occupation of several civilisations. It was the capital of the Kingdom of Sardinia (which in the 1861 became the Kingdom of Italy) from 1324 to 1720 and from 1798 to 1815. Seat of the important University of Cagliari and the Primate Roman Catholic archdiocese of Sardinia, the city is an important regional cultural, educational, political and artistic centre, known for its diverse Art Nouveau architecture, vibrant nightlife and several monuments. It is also Sardinia's economic and industrial hub, having one of biggest ports in the Mediterranean sea, an international airport, and the 28th highest income rate in Italy, comparable to several Northern cities, such as Turin, Vicenza and Genoa.