The historic centre is enclosed within Renaissance walls begun by Onorato III Caetani in 1448 and finished by Francesco Caetani in the first half of 1600s by order of Urban VIII. Access to the village is via four gates: Porta del Pozzo, Porta delle Noci, Porta San Nicola, Porta Sorda.
Curiosities are the shapes of the Bastion of the Torrenuova and the Bastion of San Sebastiano that testify the passage from the “shot plunger” defence system to the “cross-fire” defence system. Access to the castle is via the drawbridge.