The main facade of the building is presented in three levels highlighted by thin frames that underline the exclusive development horizontally.

The exhibitions of the windows are simple and the only element that distinguishes the noble floor from the other levels is the presence of a simple molding and the smooth frieze surmounted by a straight frame.

The portal is inserted in an asymmetric position with respect to the facade as if to join the amalgamation of the two distinct buildings: the one on the right of the Eroli, the one on the left of the Cardoli-Alberti.

The entrance hall is divided into three bays with lowered cross vaults and the coat of arms Eroli in key.

On the left, beyond the access to the ticket office and the bookshop, a portal of the fifteenth century is the entrance to the wing, once Alberti-Cardoli. 

On the right, however, rises the monumental staircase that leads to the piano nobile.

Now the building hosts: 

• at the ground floor, the municipal library;
• at the first floor , the Paleontological and Archaeological Collection;

on the second floor are preserved works of the Art Gallery.