The museum is hosted in the rooms on the ground floor and the two upper floors of the Orsini-Cesi Castle, which was founded in the late XII century, work of the Roman Senator Giovanni Capocci; from the descendents of whom, in 1370, it passed to the Orsini family, who, in the early 1400s, started building extensions to it, constructing four cylindrical corner towers.
After many ups and downs in 1590 the building and the stronghold were purchased by Bartolomeo and Federico Cesi, founder of the Accademia dei Lincei; at the beginning of the XVII century the Cesi family made changes to the castle to give the shape we can see today – making a courtyard and covering the large building with frescos. In the latter part of the XVII century, passing into the hands of the Borghese family, the building fell into decadence and was used as a granary.
The exhibition is composed of a prehistoric and protohistoric section, including the following subsections: Palaeolithic, Neolithic, Eneolithic and Bronze Age, Late Bronze Age, and a section in which there is an exhibition of relics from some Bronze Age sites in the territory of Monti Cornicolani: Le Caprine (Guidonia Montecelio), La Grotta dello Sventatoio (Sant’Angelo Romano), Cretone (Palombara).
In an area on the terrace of the building a plaster cast of a Palaeolithic relic that was found in 1997 in the territory of Palombara Sabina with a panel describing it.