Today the Orsini Fortress is open to the public and also houses the small Civic Archaeological Museum, which showcases ceramics and other glazed artifacts found in the Sorano area, in the so-called "butti", or medieval wells.
A small room displays three codices from Sorano and Castell'Ottieri. In the study of Niccolò IV Orsini are two groups of frescoes by an artist of the Sienese school executed between 1580 and 1585, with classical floral motifs, scenes of mythological character and the Gregorian notes of the music of a song reported in Boccaccio's Decameron.