Piazza Castello still preserves today the ruins of the old Castle, which was the largest and strongest in the city. Inside the Castle, there was a small church (closed in 1806) and a garden. After its last use as a prison, by 1825 there was no trace left of the old castle.
The square owes its name to the ancient bishop's castle, dating back to the medieval era, which stood in the area and of which today there are no visible traces. The square, characterized by a picturesque view of the Piave valley and the Dolomites, is surrounded by historic buildings such as the Palazzo dei Rettori, a testimony to Venetian rule. Over the centuries, it has undergone several transformations, becoming a space for representation and aggregation for citizens and visitors, who can admire scenic views and the architectural charm of the city.