The Antiquarium is set up inside the Torre Carlo V tower. This exhibition gathers the archaeological testimonies found during a long series of excavations lead by the Soprintendenza per i Beni Archeologici dell'Abruzzo (the Abruzzo Regional Board of the archaeological heritage). The excavations started in 1991 and have brought back to light one of the most ancient settlements within the entire Tronto valley, the Roman city of Castrum Truentinum.

The archaeological excavations have allowed to discover proto-historic remains dated sometime between the late Bronze Age and the early Iron Age.

Inside the Antiquarium a Lombard tomb exhibited, which was excavated within the area of the Tronto river in Matrinsicuro and encloses remains dating back to the 11^th-12^th centuries A.D.