Sermoneta is a walled hill village, with a 13th-century Romanesque cathedral called Cathedral of Santa Maria Assunta and a massive castle, built by the Caetani family. In the 13th-16th centuries, it was home to a flourishing Jewish community. Sermoneta is the hometown of the humanist Aldo Manuzio and the Baroque painter Antonio Cavallucci.

The territory of Sermoneta was already settled in ancient times. In its territory, near the present of the actualy Valvisciolo Abbey, site of the ancient city of Volsca di Sulmo, cited by Virgil in the Aeneid.

The free municipality, it submitted soon to the Caetani family (1297), who made it the center of their domains on the entire southern Lazio, thanks to the fortunate position on the Via Pedemontana, which had replaced the Appia in the connections between the North and the southern Italy. The sermonetani, for the control of the road and in particular the passage of customs, defeated the city of Ninfa then the neighboring Sezze. From this period dates the medieval village, perfectly preserved, the Caetani Castle and the Cathedral.

The Caetani erected an imposing castle, allowing the city to grow and expand under his protective wing. Sermoneta became the main center of a vast estate and also flourished artistically and culturally. Over the centuries, the imposing Caetani Castle and the cities , many illustrious kings and popes but also celebrities such as Leonardo Da Vinci stay in this village. Today Sermoneta still retains, intact, this immense historical, artistic and cultural, so that it became one of the most important tourist resorts on the outskirts of Rome.