Castello di Rocca San Felice, Medieval castle in Rocca San Felice, Italy.

Castello di Rocca San Felice stands on a rocky spur at 723 metres and survives as a gate inside the village, stretches of the perimeter wall and the donjon. The round donjon, built in the 12th century, measures ten metres across with dry-stone walls about 2.5 metres thick. A 1783 print shows the earlier layout: a wall circuit with two towers enclosing the village space.

The castle's construction date is unknown; it was probably built around 850 by the Lombards to defend the Duchy of Benevento against Byzantine incursions. After the Norman conquest from 1076 it was restored and enlarged. It is first documented in the Catalogus baronum (1150–1160) as Castellum Sancti Felicis, owned by Ruggiero de Castelvetere, vassal of Elia Gesualdo. A legend holds that in 1236 Frederick II's son Henry was imprisoned in its cells.

The name Castellum Sancti Felicis appears in the Catalogus baronum between 1150 and 1160, when Ruggiero di Castelvetere held it as a vassal of Elia Gesualdo. Local tradition links the ruins to Margherita d'Austria, wife of Frederick II's son Henry, said to search the site on full-moon nights.

The ruins stand on a rocky spur; the sources give its height as 750 m in one account and 723 m in another. Access is through a gate inside the village, then a first courtyard that once housed artisans and soldiers, and a second courtyard with the donjon. Parts of the curtain wall and the tower survive; the upper floors were reached by external wooden and stone stairs.

The keep's four storeys were stacked by function: a cistern with storage space on the first, a kitchen with oven and well on the second, washing and toilet facilities on the third reached by an external wooden stair, and living rooms on the fourth via an external stone stair. The sloping roof collected rainwater and channelled it straight into the cistern.