The oldest part of Dongo is the hamlet of Martinico: this is where the Romanesque church of St. Mary was built between the XI and the XII century. It has a simple facade enriched by a cruciform window and a small lateral facade dating back to the XIV century. The fresco, in the middle of the right side of the nave, was painted between 1310 and 1315 and it depicts the Madonna of Mercy with six angels holding her mantle. Other fifteenth-century frescoes are visible on the church ceiling, all on the right side. This is where is kept the most beautiful silver gilded Crucifix made by the workshop of Francesco Ser Gregori (1513).