The path towards the town of Teano crossed lands with the remains of ancient buildings barely visible among brambles and wild herbs. For those presences, the entire area was known as "the Caves" and a chapel dedicated to the Madonna had been erected there.

It was only in the second half of the 20th century that the exploration of the place and the slow reconstruction of its illustrious past began. The systematic archaeological excavations and the following restorations recovered the imposing structure of a Roman theater, dating back to the end of the second century BC. Built in opus incertum with tuff blocks, it had been the subject of a first renovation already during the Augustan age, when Teanum Sidicinum, the ancient capital of the Sidicini, was recognized as Roman colony. At that time, the theater was part of a complex that also included a temple dedicated to Apollo. Then, in the 2nd century AD, when Septimius Severus was emperor, the building underwent a further transformation, which enlarged it allowing the accommodation of five thousand people and embellished it considerably. The cavea came to have a diameter of 85 meters while the scene, 26 meters high, featured three orders of columns with statues, capitals and architectural sculptures of precious marble. An earthquake was probably the cause of the damage to the theater that led to its abandonment. And in the Middle Ages, marbles and building materials were systematically taken from it and used in the new civil and religious buildings of the medieval town. Numerous artifacts found in the theater, accompanying its history, make up a section of the Archaeological Museum of Teanum sidicinum in the late-Gothic complex of the "Loggione and Cavallerizza", dating back to the 14th century.