The Visconti Castle in Vercelli, Italy, is a medieval castle that stands proudly in the heart of the city. Built at the end of the 13th century, the castle has undergone several transformations over the years. Today it serves as the seat of the Tribunal of Vercelli. The original design, attributed to Matteo Visconti, follows the classic pattern of the Visconti castles of the Lombardy plains: square, with towers at each corner, two entrances on opposite sides, and an inner courtyard. In addition to serving as a symbol of Visconti power over Vercelli, the castle also strengthened the city walls on the south side. Over time, the castle fell into disrepair, but was restored and adapted for various purposes. During the Franco-Spanish War in the 17th century, the castle was damaged during the Spanish siege of 1638. It served as a residence for the governors of Vercelli during the Napoleonic era and later housed the prison. Further restorations were carried out in the 20th century, allowing the castle to regain its original grandeur. Today the castle can only be admired from the outside and is used internally only for official state functions.