Casa torre dei Bonacolsi, Medieval tower in Piazza Sordello, Mantua, Italy

Casa torre dei Bonacolsi is a brick tower built in 1280 featuring defensive characteristics and traditional design elements of northern Italian medieval towers. The structure comprises multiple floors with narrow window openings and thick walls typical of fortified towers from that era.

The Bonacolsi family constructed this tower during their rule of Mantua before being overthrown by the Gonzaga family in 1328. This change in power marked a turning point in the city's governance and brought new political arrangements.

The Bonacolsi took their name from the tower and palace complex on Piazza San Pietro, in the civitas vetus. After the 1328 revolt the Gonzaga took over the family properties, and in the early 18th century the Castiglioni bought the palace, which was then renamed after them. The Castiglioni were one of Lombardy's leading noble families since the 10th century; the Mantuan branch dates from 1440 and produced Baldassare Castiglione's grandfather.

The tower is today part of a private palace and can only be visited through organized tours that offer insights into medieval architecture. It is advisable to check ahead for tour availability since access is limited.

The tower is joined to the building opposite by a covered overhead passage, built around 1300 by Rinaldo Bonacolsi, the last of the family, to link the house he inherited from his uncle Bardellone. The Bonacolsi were overthrown on 16 August 1328, and the palace passed to the Gonzaga.