At the inhabited area of Lagna, a hamlet of San Maurizio d'Opaglio; the Oratory of San Rocco rises, documented several times during the 1600s as a church devoid of furnishings. During the pastoral visit of Bishop Volpi on 15 July 1629, there were numerous plants that caused damage to the church, in addition to the small stream that flowed in the area in front and which created many problems during periods of flood. In 1652, the oratory was finally provided with the necessary furnishings and therefore the license to celebrate it was given back, which had been removed after the visit of Bishop Volpi. In 1704 the precarious conditions of the building required its reconstruction; this date is shown above a window to the left of the facade.

Walking through the narrow streets of Lagna you will come across numerous frescoes of exquisite workmanship and palaces from 1600-1700 which show traces of ancient decorations.

On the path that leads to the lake stands the ancient mill of Lagna . The mill of presumable medieval origin, has stone columns to form a portico, an expensive architectural element and therefore certainly produced in an era of economic prosperity for the area.