Saint-Laurent-du-Pont is the town “of the bridge.” Here the narrow road crosses the River Guiers, turns and begins to rise sharply towards the almost secret narrow Porte de la Fourvoirie, “the gateway of the fortified road.” The name takes us back two thousand years. When Roman soldiers entered the Valley they were so sure that this pass could be impregnably defended that they called it Forta Via, “the fortified entrance.” Forta Via, on the modern maps, has become Fourvoirie. The gateway of La Fourvoirie is a narrow cleft in the five-thousand-foot granite wall. Through the mountainous barrier, the turning and twisting pass cuts inward and upward to the high secluded interior valley. There would be no gateway at all had it not been for the erosion of the rock, over millions of years, by the River Guiers. The fast-flowing water has cut a slot three thousand feet deep in the wall of granite. The rock has given way. The other defenses of the Valley have not.