Col du Mont-Cenis (Colle del Moncenisio) is a high mountain pass at an elevation of 2,083m (6,827ft) above the sea level, located in Savoie, France, which forms the limit between the Cottian and Graian Alps. It's one of the highest mountain roads of the Alps.
The pass connects Lanslebourg-Mont-Cenis in France in the northwest with Susa in Italy in the southeast. Col du Mont-Cenis was the border between France in Italy until 1947 Treaty of Paris, when it passed completely to France.
The pass has been featured several times in the Tour de France and the Giro d'Italia bicycle races. There are 2 ways to get this pass: From Lanslebourg, the ascent is 9.84 km long. Over this distance, the elevation gain is 682 meters. The average percentage is 6.9 %. The climb includes a famous sequence of five hairpins. The surface of this wide road is very regular, with a slope constant of 7%. And starting from Susa, the ascent is 30.51 km long, and the elevation gain is 1.581 meters. The average percentage is 5.2 %.
Both sides of the road are wide and well surfaced. The site around the lake at the top is pretty busy on weekends with locals and tourists. Some historians believe this pass was used by Hannibal when he made his famous elephant Alps crossing. It is very nice up around the lake and there are many rough-stuff routes to explore for those with a mountain bike. People have been crossing the Col du Mont Cenis for thousands of years. Both Constantine the 1st and Charlemagne crossed the Pass with armies. It was the most frequently used passage between Italy and France in the middle ages. When the French ports were blockaded by the British after the battle of the Nile, Napolean ordered an improved road built over the pass. Finished in 1810, it allowed carts and carriages to be able to make the crossing.
The pass is traversed by D1006 road. It’s seasonally closed. There are sheer drops virtually along the entire route and enough hairpins to make a whirling dervish dizzy. On the French north side, the pass is open between 15 May and 31 October. On the Italian south side, it is open the year around. On both sides the maximum grade is 11%. A quick glance at the map at its sheer drops and serpentine twists and turns, confirms that this is no hype.