Trontano is a small town at the entrance of Val Vigezzo, overlooking the plain of Domodossola and surrounded by its hamlets, "small masterpieces of spontaneous architecture in which the wise use of beola and serizzo represent a model of hamonious adaptation to the environment". The XIII century tower of Creggio, a building damaged in the XV century and then rearranged by the will of Lodovico il Moro after the battle of Crevola (year 1497), seems to have been a refuge in the XIII century by the heretic Fra Dolcino. Indeed, according to an anonymous chronicle of the XIV century, the head of the "apostolic" movement was born in Trontano, while for others he was a native of Valsesia, where in 1307 he was burned at the stake and his followers massacred.
