North is at the top in the photo. This is the Monte di Verna plain just a mile to the SW of Caiazzo, north of Naples and Caserta. The clump of buildings in the middle is a modern dairy processing facility. The tell me that whatever is left of the old Bourbon Pheasant Grounds is the small building shown in the insert (the photo is from c. 1970) and is somewhere on the premises of this facility. The river running below the diary plant is the Volturno. The plant is still called the Fagianeria --Pheasant Grounds.
One of the most interestings sights/sites in Caiazzo is the Roman cistern beneath what is now Piazza Giuseppe Verdi. The cistern is dateable to the 2nd century AD. It is a rectangular brick construction mounted by a barrel vault. It measures 23 x 4 meters—AND—you can visit it! Not independently, of course; you have to call city hall and get permission, but you can do it. As a matter of fact, I have a friend who did it. He runs the Napoli Underground website and the story of his adventure is on that site in English translation (by Yours Truly) at this link. There is more photography, as well.
update: April 5, 2016
Cyclopean walls - As noted in this entry on Fiuggi:
The history of the towns in Ciociaria go back much further than the Middle Ages, however— even further back than the Romans. Many medieval structures, such as the cathedral of Anagni, are built on the very sites of ancient structures built by pre-Roman Italic peoples, such as the Hernici or the Volsci. The megalithic walls of Fiorentini, for example, are from the fourth century, b.c.; they are still well-preserved and intact for virtually the entire perimeter of the city and look as sturdy today as when their Italic masons, the Hernici, built them. In Alatri, the ancient acropolis contains the best preserved example of pre-Roman "Cyclopean" —gigantic— walls anywhere in Italy. On the remnants of that acropolis now rises the Cathedral of Alatri. Moving on to Arpino, one finds a town which, according to legend, was founded by Saturn, himself!
These remnants of pre-Roman Italy are found in many places on the peninsula, including Caiazzo. (See Cyclopean in the main index). Caizzo is in the Volturno river valley just below the Monti Trebulani (alias the Colli Caprensi), a massif in the heart of the province of Caserta. It is separated by that valley from the larger Matese massif and the main chain of the Campanian Apennines. It is karst country (caves, stalactites, underwater currents) and very good hiking and exploring for cavers. But there are also the overgrown ruins of the Cyclopean wall (photo, above, right) that presumably surrounded a pre-Roman settlement of the Oscan-Samnites. Even more mysterious is the lettering on one of the stones.
photos in bottom section: courtesy of Napoli Underground