The Roman Theater of Teanum Sidicinum was built at the end of the second century B.C. .. The Theater was part of an architectural complex consisting of a large artificial terrace where also a temple that appears to have been dedicated to Apollo. When, in the early third century A.D., the theater was completely renovated to imperial will, on impulse of Septimius Severus and completed by Gordian III, he assumed grandiose form. In the late ancient and medieval era on the ruins of the building, probably collapsed in an earthquake, he planted a yard for the recovery and reuse of marble architectural materials. Between the twelfth and thirteenth centuries the now underground auditorium was built a workshop area for brick and ceramics production. In the modern era of the old theater he was still just a vague memory. A country lane passing the ruins of the scene, mounted on the now almost buried structures and slipped under the vaults of the ambulatory median and then go out and continue to the medieval center. The look decrepit and mystery of the ruins caused him to name the area as "the caves" and, in the interests of the traveler, was installed a chapel with an altar dedicated to Our Lady. The first systematic exploration of the monument were conducted in the early 60s of last century by Werner Johannowsky. After several interventions of excavation and restoration in the late '80s, starting from 1998 was conceived a complex project of exploration, restoration and enhancement of the site, which lasted more than a decade. The discoveries have occurred over the years made it possible to clarify many aspects of the monument and the restorations carried out, both with national funding both with EU funds, allowed to return to public use the old building, which could also accommodate important plays. At the Theater of Teano it is devoted an entire sector of the Archaeological Museum of Teanum Sidicinum with models reconstructing the complex in its different phases, architectural remains, including lintels and richly decorated capitals, and systems of great value sculptural.