The Swabian Castle of Bari is an imposing fortress dating back to the thirteenth century , now used as a museum; located on the edge of the historic center, near the port area and the Cathedral, with its bulk it represents one of the most important and well-known monuments of the city. Historically attributed to the Norman king Roger II , the Castle was built in 1131 on pre-existing Byzantine housing structures and, after the hard intervention of William I the Bad , was recovered by Frederick II of Swabia between 1233 and 1240. In the second half of the 13th century , Carlo d'Angiò implements a restoration program aimed at reinforcing the north wing of the Castle, at the time lapped directly by the sea. In the 16th century, Isabella D'Aragona and her daughter Bona Sforza radically transformed the Castle, adapting it to the development of heavy artillery with the construction of a mighty bastion wall around the Norman-Swabian nucleus. In the following centuries, especially during the Bourbon domination, the Castle underwent a substantial abandonment, becoming first a prison and then a barracks. Only in 1937 it became the seat of the Superintendence of Monuments and Galleries of Puglia and Basilicata.

The Norman-Swabian nucleus has a trapezoidal plan, with a central courtyard and three high strongly ashlared corner towers. Going over the southwestern tower, known as the Minor's because it housed the prison section in the nineteenth century, you will find the original entrance, the Frederick's portal that leads into the central courtyard. Today there are three halls and a small chapel with classic shapes. In the 16th century, the Aragonese duchesses carried out a radical transformation of the complex. Inside, the Castle takes on the appearance of a Renaissance residence, with an elegant and scenic double flight of stairs that connects the ground floor to the large halls of the noble floor.

In the rooms of the west wing on the ground floor of the Castle there is the Gipsoteca , a collection of plaster reproductions of the sculptural apparatus of the most important Apulian monuments and cathedrals created in 1911 by the sculptors Pasquale Duretti and Mario Sabatelli. Also on the ground floor it is possible to visit two small areas of archaeological excavation, where pre-existing structures from the Byzantine era are visible. In the S ala Aragonese there is a permanent photographic exhibition on the history of the restoration and functional recovery of the Castle carried out during the twentieth century. In the Sala Angioina , the archaeological collection of ceramics from the excavation of the castle's “butto”, datable between the fifteenth and eighteenth centuries, has been housed. In the Norman Room , erratic stone materials are exhibited, while the room on the first level of the Tower of the Minors contains precious materials. The two largest spaces on the main floor, the Sala Bona Sforza and the Sala Federico II , are destined to host temporary exhibitions and cultural events.