The Castle was built between 958 and 978 on the area of land called Romano.
The inhabited area around the castle began to develop after the decline of the nearby Castello Apollonio, destroyed in 1125 as a consequence of its long standing conflict with Tivoli.
The only visible façades are those facing the town, which have a hanging garden. The entrance wall is simple, with an ornate textured gate. The gate leads into a courtyard which has cloisters on three sides, with round arches and columns. These are decorated with classical freizes, which include an inscription in memory of the builder, Porcelo Orsini, and an image of the god Mithras. A large salon on the ground floor leads through to the ancient dispensaries and the castle prisons which are two small cells. The upper floor is reached by climbing a staircase that dates to 1300. This floor, the piano nobile, has been completely restored and furnished, as a plaque in the great salon attests. The salon has a wooden ceiling, lavish tapestry and other large paintings. The floor also holds four more rooms, all decorated with era-appropriate furniture and paintings.

Galleria fotografica