Once, it stood in the north outskirts of the town and was the only church of the San Leonardo hamlet, one of the first bonded burghs of the Novara region, which gave rise to the present town in the course of the XII century after the union with "Burgi Mayneri". Today, the oratory is completely inserted in the town urban fabric (Via Don Minzoni). It has a nave with semicircular apse. The façade is saddleback and the entrance is overlooked by a lunette and a luminous cross opens above it. The wall system appearing on the façade and in the counterforts is made of large square stones, whose horizontal course is bound by white mortar, while river stones appear on the side walls and on the apse; they are irregularly arranged with some herringbone stretches. The frescoes decorating the interior of the building, probably of Romanesque inspiration, are very interesting. The decorations covering the oratory walls are still deeply studied by critics and historians of arts. They have recently undergone a good conservative restoration.