The Palazzo Caetani in Cisterna di Latina was constructed in 1564 by the architect Francesco da Volterra. It houses the Pinacoteca Civica, the Municipal Library and a Museum dedicated to the Butteri and their horses. During the summer months, there are also concerts.
Palazzo Caetani Cisterna di Latina
Useful information

Address: Piazza XIX Marzo – Cisterna di Latina. Phone: +39 06 96834246.
History and description
Francesco da Volterra had been commissioned by Bonifacio Caetani to build the palazzo. The architect used the already existing Frangipane fortress as the basis for his design. This included two towers and an interior courtyard.
Having been seriously damage during World War I, the building was completely reconstructed.
Caves of Palazzo Caetani
The main attraction of the Palazzo Caetani is a network of underground tunnels that starts underneath the building. These Grotte di Palazzo Caetani branch out below the center of the old city. Only part of the tunnels can be visited, since a big section has not been explored yet. Some of the tunnels are 15 meters below ground.
According to one legend, the tunnels were constructed by Nero, to be used as water conduits for his Villa of Neptune. Others think that the tunnels were used by the Caetani, to be able to flee to one of their other properties, in case the palace was under attack.
During World War II, while the city was being bombed, 4,000 inhabitants of Cisterna spent 58 days in the tunnels.