During work to restructure piazza Mercato and piazza Sant’ Agostino at Arienzo (Caserta) an archaeological investigation was undertaken in order to ascertain the presence of any ancient remains on the site. Excavation revealed a road identified as the pomerium surrounding the town of Arienzo. Subsequently, walled structures probably belonging to the Aragonese (15th-16th century) phase of the town walls were found. Although the area was already partially compromised by the presence of a garage, intact stratigraphy was recovered below a layer of volcanic ash from the 1631 eruption of Vesuvius. The stratigraphy produced a number of datable pottery fragments and coins dating from between the end of the 15th century and the mid 17th century, the period when the Aragonese dominated the kingdom of Naples. Moreover, the excavations led to the discovery of the base of one of the towers which was part of the West Gate of the Aragonese town. This gate already appeared in a town plan that was roughly drawn up by Tommaso Cognetta in 1696. Lastly, a dry-stone wall built of limestone was identified. Its sloping line would seem to confirm the hypothesis regarding the existence of a defensive ditch which is described in a Spanish document of 1531, kept in the “Archivo General de Simancas” at Valladolid in Spain.