Alghero (Italian pronunciation: [alˈɡɛro]; Catalan: L'Alguer, pronounced: [ɫəɫˈɣe], locally: [lalˈɣe]; Sardinian: S'Alighèra; Sassarese: La Liéra), is a town of about 44,000 inhabitants in Italy. It lies in the province of Sassari in northwestern Sardinia, next to the Mediterranean Sea.The name Alghero comes from the medieval Latin Aleguerium, meaning stagnation of algae (Posidonia oceanica, actually a seagrass) on the coast. The Catalan language is co-official in the city, unique in Italy.