An ancient fortified town in the province of Cremona, situated on the Eastern shore of Lake Gerundo, Castelleone has ancient origins, evidenced by finds of the Mesolithic era, preserved in the Civic Archaeological Museum. It was inhabited by Insubrian Gauls, Celts, Romans and the Lombards and was destroyed by Barbarossa in 1186, along with other fortifications of the town. Two years later the Bishop of Cremona Sicardo obtained the permission to rebuild the Castrum Leonis on the old site of Castel Manfredi. For the historians, the town's name was attributed to Pope Leone, that gave this stronghold this name, due to its strategic location, during the period of the struggles between Guelphs and Ghibellines.
Among the sites of major historical, artistic and architectural heritage of the area, worth of mention are:
- The Shrine of Our Lady of Mercy, built outside the city center, to commemorate four apparitions of Our Lady, that took place, according to tradition, in 1511;
- Tower Issus (or of the Lion), dating from the XI century, is the only defensive element of the ancient village of Castel Manfredi, saved from the attack by the Barbarians of Frederick Barbarossa;
- The Church of Santa Maria in Bressanoro, built in the XV century on the will of Bianca Maria Visconti, following the miraculous healing of her daughter, and features inside valuable frescoes in the late XV century;
- The Parish Church, built in 1551, where once stood an old church of the XII century. Although the façade is in Renaissance style, the interiors have a Baroque style taste.