The former abbey of Santa Maria at the hamlet of Fornelli is the oldest and most architecturally interesting building in Mallare. Built in 1179 in a Gothic-Lombard style, it features a central nave flanked by two aisles, with tunnel vaulting overhead and traces of frescoes surviving on the interior walls.
The structure has been altered over the centuries but retains the essential character of its original Romanesque-Gothic form. It is considerably more rewarding than the later parish church, and the walk out to Fornelli through chestnut woods takes about twenty minutes from the village centre.