The castle of Barletta is the architectural result of a series of stratifications due to the succession of several dynasties in power, succeeded from the 11th to 18th centuries. Once defensive fortress, encircled by the sea that occupied the moat all around the castle and isolated from potential enemy attacks, is a strategic point in town life as well as an important city planning point. It is home to the Municipal Library, the Civic Museum and a conference room and exhibitions. Among the works preserved, besides a presumed bust of Frederick II of Swabia in limestone dating to the thirteenth century, here is the Sarcophagus of the Apostles, a high relief in stone first witness of Christianity in Barletta, dating back to the period between III and IV century. The castle is located in the homonymous square in the Santa Maria district, close to the Santa Maria Maggiore cathedral and the castle. The size of the outer sides of the castle, measured at the base of the corner ramparts frame, varies, with the east face being the longest of all, about 127 meters, the west face, shorter than three meters, and the south and north, both about 120 meters long. The diagonal between the bastion tips measures about 125 meters, with two orders of overlapping casemates of 16 meters in diameter. The height of the west prospect, the highest one due to the presence of the factory body of the Artificial Lab, is approximately 24 meters, while the lower north face, the maximum height is 19 meters. The walls of the castle have a thickness varying from 5 to 12 meters and are made of limestone cut into squared blocks and just rocks, most of which were derived from the buildings destroyed during the sack of 1528. It is surrounded by the gardens, called the brothers Deer, on all sides except the north face, and separated by the deep and deep moat, which at the lowest point reaches ten meters in depth with respect to the footbridge of the castle access deck. The building has a polar quadrangular shape, with its characteristic pentagonal bastions lanceolate on the four edges and the four arms of the building that combine them. In the middle is the square courtyard. All the chambers of the castle are vertically divided into three parts: the lower part with the slight shoe stand ends at the top with a rather protruding bull molding, in some cases interrupted by the presence of the cannons; The first elevation, which sees the presence of gutter slits and other small ventilation slopes, characterized by the typical stone of the castle, the upper part of the exposed masonry is crowned by a merlature. The entrance to the castle is preceded by a slargo, called the "square of arms", in front of which the rivellino rises. Once this first access is over, you are in front of a three-arch masonry bridge. The entrance door opens to the center of the southern facade and has a rectangular entrance embedded in an archway. The quadrangular entrance is dominated by a lintel decorated with decorations and a stone slab bearing testimony to the delivery of the castle, as we see it, in 1584. Near the main entrance of the gardens, located on the board with the rivellino, finds place the historic ornamental fountain, strongly wanted by soldiers in the Military District and inaugurated on November 11, 1941. After the rivellino, until the restoration of the Grisotti the castle's entrance bridge was supported by three massive vertical pylons and as many arcades as well as an arch of smaller dimensions that connected the last pylon with the castle dating back to the nineteenth century, so after the removal of the wooden drawbridge, with the replacement of wooden beams.