Calendasco castle, or Castrum Calendaschi, is a fortress built in the 9th century and cited for the first time in a document by Pope Urbano II. In 1346 it was demolished by Piacenza inhabitants and then rebuilt in 1372 by the Guelphs to defend themselves from the Visconti family.
It looks like a trapezoidal building constructed in bricks with Guelph merlons, surrounded by a moat and with three doors, two of which still show the remainders of a drawbridge. Today, these bridges are in built in bricks.
The main entrance is protected by a cylindrical tower and leads into the courtyard with a double loggia. The castle, because of the importance of the port on Po river and the constant flow of goods and people, played a pivotal defensive role also collecting duties. According to archival documents, the noble family that controlled the fief and lived in the castle longer than any other owner were the Confalonieri. Official documents record their presence on a time span of about 200 years, from the 15th century to the 16th.
The castle today belongs in part to private owners, and in part to the Municipality of Calendasco.