The Palazzo Orsini dominates the western end of the tuff spur, its bulk visible from the valley far below. It was built and extended by successive Orsini lords between the 13th and 16th centuries, incorporating an earlier fortified tower into an increasingly palatial structure as the family grew in power and pretension.
Today it houses the Museo di Palazzo Orsini, which holds Etruscan finds from the local area, medieval and Renaissance artworks, and the separate Jewish heritage section (see La Piccola Gerusalemme). The palace itself is the main attraction — the courtyard, the painted rooms, and the views from the upper windows over the valley are worth the admission alone.
Attached to the palace on the town's main approach is the Fortezza, a 16th-century defensive structure with the Orsini arms above the gate. From the ramparts and the narrow street alongside, you get the best views of the tuff cliffs below and the town's extraordinary setting.