Castello di Montalto, Medieval castle in Castelnuovo Berardenga, Italy.

Castello di Montalto is a medieval castle in Castelnuovo Berardenga featuring a watchtower that rises above the Tuscan landscape. The structure comprises multiple residential buildings and apartments that now serve as guest accommodations, with space for approximately 44 visitors.

The tower was probably built by the Longobards in the 6th or 7th century, while the main castle was erected during the first millennium by descendants of Winigis, first count of Siena, and his son Berard, from whom the Berardenga takes its name. In June 1208 the Battle of Montalto left the castle almost entirely destroyed and Florence took over 1200 prisoners. Siena backed the rebuilding, and in 1251 the castle passed under direct Sienese control. Restorations followed in the 16th and 19th centuries.

The name Berardenga comes from Berard, son of Winigis, the first Frankish count of Siena; his descendants, the Berardeschi, gave the land their name. In the Sala d'Armi, frescoes on the upper walls show the castle's 16th-century farmhouses and vignettes of hunting and farming on Berardenga land. A fresco inside the entry tower depicts Saint Martin sharing his cloak with a beggar.

The site operates as guest lodging, with different houses and apartments available for stays. Visitors should plan ahead, as the property functions by reservation and is not always open for casual visits.

The property houses a consecrated chapel with room for about 60 people, serving both Catholic and Protestant ceremonies throughout the year. This dual religious function makes the site an uncommon gathering place for different faith communities in the region.