Are clearly visible in the walls and the entrance of the area. The spiazzo which opens immediately after the input, hosted the homes of craftsmen and soldiers. Passed another input, also fortified, one enters into the courtyard from which access is gained to the donjon.
The most ancient nucleus of the fortification is constituted by a cylindrical tower of the XII century that incorporates the previous defensive structures, and by murazione cinta in which, along the southern side, opened the inlet, formed in the bank of calcareous rock. Constituted by a cylinder that is not devoid of momentum despite the 10 meters in diameter, the tower is founded on the rock and built with the technique of the filling to the "sack" (opus caementicium) within curtains of limestone ashlars of irregular shape (opus incertum). The walls, which have the thickness of m. 2.50, employ as supports of the ashlars of paraments, fragments of tiles and tiles. The tower is built on four floors.
In the first find place the tank for water supply and a room for stowage of provided and timber (depot); the second floor, equipped with single lancet windows and receptacles on the wall for the deposit of objects and the housing of lucerne, performed the functions of kitchen, as is clear from the presence of the well and the oven-fireplace. A residential functions were intended for the last two floors: the third, provided with toilet, washbasin and a space-window, was accessible from the outside thanks to the input port, placed up for safety requirements, which was reached through a wood structure anchored to the masonry by tie rods. To the right of the door, a scale formed in wall thickness, allowed to climb on the fourth floor, witnessed by a few ruins. The cover, used for sighting and defense, was also the fuzioni of impluvio for the purposes of water supply; a pipe fictile brought the water to the cistern, served from the well of the kitchen.
The first construction, which took place around the 850, was a fort where dwelt a captain with his squad of soldiers with the task of monitoring the border of the Principality of Benevento at that point was marked by the river Fredane. When, in 1037, was instituted the law on inheritance of the feuds, the feud of Rocca San Felice had a lord and the fortress underwent major enlargement works and was transformed into a castle. After the 1076 with the conquest of these territories by Roberto il Guiscardo, the castle of Rocca San Felice passed under the dominion of the Normans. In 1147 the feud belonged to Ruggiero of Castellovetere and in 1180 to Elijah di Gesualdo. In 1535 the lord of the castle was Hannibal Caracciolo and in 1591 is, instead, that the ceded to the Royal family. The last Lord of Rocca San Felice was Giovan Francesco Capobianco that maintained the feud for a long time and right up to the eversion of feudalism in 1806.