The Piano San Giovanni Archaeological Park in Canosa testifies to the urban development and cultural growth of the town at the behest of Bishop Sabino.

Svevo Castle is located on the entrance to the old village of Termoli and it is the most representative defensive building of entire Molise coast. It was built around the 13th century, entirely in limestone and sandstone, to secure a defense both from the sea and from the mainland. The castle was defended by a sturdy wall in which were inserted the cylindrical towers and perfectly preserved is the one that anticipates the entrance arch of the old town. During Longobard domination, the inhabitants of the small feudals existing in the territory, given the increasing number of sea-related aggressions, they took refuge on the small promontory and built a fortified enclosure. The definition of Svevo seems to have been attributed afterwards the renovation and fortification required by Federico II of Svevia, who, cultivating the dream to reunite Germany and Italy under the same domain, designed a military program that transformed Norman fortifications in sight and signal towers.