The imposing entrance, traditionally known as the Spanish Gate, is a rare example of regional architecture, built with rustic ashlars as part of the city walls. It was constructed, within a large-scale project to reorganise the castle’s external defences, by Sigismondo Thun, an illustrious member of the Thun dynasty. His coat of arms, carved in stone and bearing the date 1566, stands out on the keystone of the portal.

Beyond the Spanish Gate, at the end of a raised walkway, you reach the Porta Blasonata recovered from the mighty 16th century walls. It leads to the Gallery of the Cannons, which once housed a set of twelve valuable bronze falconets, commissioned in 1554, two of which are now preserved in a room in the castle.

The mighty encircling wall, built around the middle of the 16th century, was commissioned by Sigismondo Thun. It has four corner towers: those at the Spanish Gate known as delle Polveri (Powder Towers) and, on the rear side, those known as ‘Basilio’s Tower’ and ‘Library Tower’, the latter is so named because in recent times it has housed the family library, in the vast room decorated with refined stuccoes.

As in all castles chosen as aristocratic residences, the open spaces were used as gardens, with ornamental plants and dedicated to rest and relaxation, and as kitchen gardens, for the cultivation of foodstuff. A lavish project, coordinated by the museum in partnership with local organisations, intends to restore these spaces as they were described in the past.