Susa is a town and comune in the Metropolitan City of Turin, Piedmont, Italy. In the middle of Susa Valley, it is situated on at the confluence …Susa is a town and comune in the Metropolitan City of Turin, Piedmont, Italy. In the middle of Susa Valley, it is situated on at the confluence of the Cenischia with the Dora Riparia, a tributary of the Po River, at the foot of the Cottian Alps, 51 km west of Turin.