The area of the city of Alba is situated at the confluence of the rivers Tanaro and Cherasca; therefore, the morphology of this land is linked to the actions of these rivers: in facts, their waters, eroding the hills, have created both deep and large valleys.
During the Quaternary period (last 2 million years), the paths of the river Po and of its tributaries (Tanaro, Dora Baltea, Belbo, Scrivia) have been subjected to several deviations. It’s remarkable the modification of the course of the river Tanaro – dated back to the passage from Pleistocene to Olocene (10.000 years ago) – that has caused the shift of the confluence between Tanaro and Po rivers from the zone of the city of Carmagnola to the one of Valenza. This action determined a generalized erosion with a heavy deepening of the riverbed and the creation of the current hills.