the construction of the Aragonese Castle of Venosa began in 1470 by Duke Pirro del Balzo in the context of a project of fortification wider. This is an imposing building in a square plan with four cylindrical towers. The coat of arms of the Balzo, the radiant sun, is visible on the west tower. The construction of the castle and the excavation of the moat in compliance with new doctrines fortificatorie entailed the demolition of the romanesque Cathedral and the neighborhood that surrounded it. It was therefore constructed a new cathedral in an expansion of the inhabited area on the lower part of the plateau where the town rises. From the fortress was transformed into a genteel residence by Carlo and Emanuele Gesualdo, with the addition of internal loggia, of the north-west and reduced to the base of the towers, and hosted by 1612 the Academy of growing.
The four cylindrical towers at the corners are incurred by reduced that constitute the shoe of the moat, used as prisons, and the entire building, which is accessed via a drawbridge, is surrounded by a deep moat. Inside there is a large courtyard surrounded by a Renaissance loggia. In front of the castle there is instead a arcaded square and a Monumental fountain granted to Venosa by Charles of Anjou. To its inside, in environments formed in the bases of the towers, the castle houses the Venoca National Museum, that preserves especially the rich testimonies of the roman colony of Guiscardo.