It is a small town in the Swiss canton of the Valais , located at the foot of the northern slope of the Simplon Pass , on the right bank of the Saltine stream , and a little above its junction with the Rhone . It is a picturesque small town in Upper Valais , situated at the foot of the northern slope of the Simplon Pass , on the right bank of the Saltine stream , and a little above its junction with the Rhone .