Castello Caetani is undoubtedly the symbol of Sermoneta and its main tourist attraction. It experienced its period of greatest fame and glory during the 1400s with the addition of noteworthy architectural and artistic features including frescoes which went to adorn the various rooms inside the castle. The castle underwent further modification when the Caetani family fell into disgrace and were replaced by the Borgias. Under Pope Alexander VI and his daughter Lucrezia, Antonio da Sangallo was commissioned to carry out the restoration work which transformed the building into a military stronghold, equipped to withstand firearms.
The castle was plundered by the French in the late eighteenth century, used as a granary in the following century, with terrible damage to the frescoes, then restored at the beginning of the twentieth century by Gelasio Caetani, the romantic philanthropist of the Giardino di Ninfa, and restored again after the Second World War.
Still imposing and practically intact today, the fifteenth century frescoes are partially preserved in the “painted chambers” – this first with rural scenes, Pan and nymphs in luxuriant countryside, the second depicting virtue, with historic figures and philosophers. Perfectly integrated with the small town of Sermoneta, which has shared its adventures over the centuries, the castle is now in the hands of the Fondazione Roffredo Caetani, and throughout the year is a venue for major events, concerts, conferences, courses in architecture, town planning and music; and in summer it hosts the Festival pontino, now in its 50th edition. The characteristic and unmistakeable appearance of a medieval town, with its side streets, alleyways and squares all inside the town walls, lend Sermoneta an ancient flavour and appeal which invite tourists to discover it in all its unique and unrepeatable charm.