In the past, the most important basin on the Island was, for a long time, the largest in Europe and is currently a tourist attraction rich in history and charm. The Omodeo lake stretches for almost 30 square kilometres, belonging to eleven Municipalities in the province of Oristano, in the historical territory of the Barigadu. It is formed by the barrage on the Tirso river: from 1924 until the end of the 20th century the river was closed by the 'historic' dam of Santa Chiara. The barrage designed by Angelo Omodeo for regulating the course of the river, for producing energy and for irrigation, was built in five years by 16 thousand workmen and was inaugurated by Victor Emmanuel III. In 1941, while the Second World War was underway, the dam was attacked by torpedoes from British aircraft. It was replaced by a new one, which was a hundred metres high and 582 metres long, named after Eleonora d'Arborea, built in 15 years and inaugurated in 1997. The previous barrage was partly submerged by the new construction.