Certainly Crussol must have been as nearly impregnable a fortress as any of its class ever built, for from its eastern flank one may drop down a sheer thousand feet and then fall into the whirlpool waters of the Rhône. This was sure and sudden death to any who might lose their footing from above, but it was also an unscalable bulwark against attack. The panorama which opens out from the platform of the ruined chateau is remarkable and extends from the Alps on the east to the Cevennes on the west, and from the Vivarais on the north to the distant blue of the Vercors on the south, and perhaps, at times, even to Mont Ventoux in Vaucluse. CHAPTER XXI IN THE ALPS OF DAUPHINY In the high Alpine valleys back of the Barre des Écrins is a frontier land little known even to the venturesome tourist by road, who with his modern means of travel, the automobile, goes everywhere. The conventional tour of Europe follows out certain preconceived lines, and if it embraces the passing of the Alps from France into Italy it is usually made by the shortest and most direct route. If the Saint Bernard or the Mont Cenis route seems the shortest and quickest, few there are who will spend a day longer and pass by the highway crossed by Hannibal, even though they would experience much that was delectable _en route_. Southeast from Grenoble and Vizille is Bourg d'Oisans, the end of a branch railway line, and a diminutive, though exceedingly popular, French Alpine station. To the traveller by road it is the gateway to the high Alpine valleys of Dauphiny, whose heart is the palpitating mountain fortress of Briançon, the most elevated of all French cities. The highroad between Bourg d'Oisans and Briançon, really the only direct communication between the two places, was begun by Napoleon, that far-seeing road-builder whom future generations of travellers in France have good reason to rise up and call blessed. The roadway climbs up over the Lautret Pass, leaving the Galibier--the highest carriage road in Europe except the Stelvio--to the left, finally descending the southeastern slope and entering Briançon via Monetier-les-Bains, just opposite the famous Barre des Écrins, the highest of the French Alps, a peak of something over thirteen thousand feet, the first ascent of which is credited to Whymper as late as 1864. Briançon's chateau, or rather Fort du Chateau, is no chateau at all, being a mere perpetuation of a name. Its history is most vivid and interesting nevertheless. Briançon itself is one vast fortress, or a nest of them. The bugle call and the tramp of feet are the chief sounds to awaken mountain echoes roundabout. It has rightfully been called the Gibraltar of the Alps, and commands the passage from France into Italy.