The monumental complex of Monte Castello comprises three elements of remarkable historical, cultural, and religious interest: The feudal Castle of the 12th century was built between 1150 and 1178, mentioned in the Catalogus Baronum among the possessions of Roberto di Lauro. Today, only some portions of the massive quadrangular main tower, called Castellone, remain of the Norman fortress. The Sanctuary of Maria SS. della Misericordia, built in the 17th century on the remains of a pre-existing small chapel, is dedicated to the patroness of Castel Morrone and is locally known as "Chiesa 'e Castiello". The church has a single-nave layout with an altar from the 18th century and frescoes dating back to the late 17th and early 18th centuries. The Tomb of Pilade Bronzetti is a commemorative monument in memory of the Battle of Volturno in 1860. It established Castel Morrone as the Thermopylae of Italy; here, three hundred "camicie rosse" (red shirts) fought against the army of five thousand Bourbon soldiers. Designed and sculpted by Enrico Mossutti, it was inaugurated on December 8, 1887, and included among the "Places of Memory" for the 150th Anniversary of the Unification of Italy.