Palazzo Caetani, Renaissance palace in Cisterna di Latina, Italy

Palazzo Caetani is a Renaissance palace in Cisterna di Latina featuring two towers and an internal courtyard paved with cobblestones, with an ancient fortress tower integrated into its irregular layout. The building now houses the municipal library, an art gallery, the Museum of Butteri and Horses, and several exhibition spaces.

Duke Bonifacio Caetani commissioned architect Francesco da Volterra to build the palace between 1560 and 1574 on the remains of the Frangipane fortress. The construction blended elements from the existing fortification with new Renaissance features.

The Zuccari Hall, also called Sala del Vescovo, was one of the Caetani reception rooms; its wall frescoes are attributed to the Marche-born brothers Federico and Taddeo Zuccari. They depict the family's holdings at Ninfa, Sermoneta and Circeo, the sea and countryside, and a view of the Pontine marshes in the 18th century.

The palace stands on Piazza XIX Marzo, and the entrance door is reached by a broad shallow flight of steps. Part of the underground caves has been restored and is open to the public, while the rest of the network remains closed after wartime damage and rebuilding. The building is shared with the municipal library and a university laboratory, so some rooms are not visitable.

The caves under the palace and the old town reach depths of up to fifteen metres, and their purpose is still debated: a legend links them to Nero's cisterns, which supposedly gave Cisterna its name, while excavations confirmed catacombs used by the early Christian community of Tres Tabernae. Most likely they were tuff and pozzolana quarries worked from the Middle Ages to the 16th century, whose material built the palace itself.