Located 1,85 miles (3 km) from Mont-Saint-Michel, Mont Tombelaine extends on a route full of pitfalls: dangerous river (the Selune), shifting sands, and sometimes potholes. On its eastern end, Pic de la Folie (Madness Peak) culminates at 147 ft (45 m) amid the brushwood. Mont Tombelaine once housed a priory, a shopping street, and a fortress. The English soldiers attempted to take Mont-Saint-Michel during the Hundred Years' War and unsuccessfully stayed there from 1418 to 1450. Mont Tombelaine was bought by the French government in 1933.