Quassolo rose originally as a castle, built around 1228 by Ivrea to defend the Strada di Francia. In later centuries the area was populated by farmers. The Praja plateau at an altitude of 640, became a convenient pasture, the dwelling became steep terraced vineyards and the beautiful river valley was checked with ingenious dams and canals to oppose the raging floods of the Dora. Quassolo is still the only town in the valley that owns land on both sides of the Dora Baltea.