Located about 10 kilometers from Annecy in France, the Gorges du Fier is one of the easier slot canyons to walk through. That’s because visitors go through the canyon on a railed walkway that is about 30 meters (100 feet) above a river rushing below. Previous visitors say people who are afraid of heights may want to avoid this. They also say to use caution on the walkway when it’s wet. The canyon is so narrow in spots, visitors can touch both sides.