2. Millau viaduct bridge, France
Towering over the Tarn River valley, the Millau Viaduct is a triumph of engineering and a modern icon of France. Soaring 1,125 feet above the valley, it’s the tallest bridge in the world, its sleek pillars seeming to pierce the clouds. The views are absolutely breathtaking—but if you fear heights, crossing it becomes a true courage test. Gliding this high above the world, with only a slim roadway under your wheels and endless sky all around, is as thrilling as it is intimidating.