The Sessera Valley (Valsessera or Valle Sessera) is a splendid natural oasis in the province of Biella. The river for which it is named flows into the River Sesia in the province of Vercelli. The valley peaks with the 2,556m high Monte Bo, in the foothills of Monte Rosa. Historically used as pastureland, the valley has pistes for downhill and cross-country skiing, and large industrial structures on the lower slopes.
Valsessera is inscribed as a Site of Community Interest in the European network, Natura 2000, along with some of the neighbouring territory of Valle Cervo. The valley also includes part of the Zegna Oasis, a significant natural area in the Biella area.