5. Zion Narrows - Zion National Park, Utah, United States

Occasionally, hiking trails require one to get a little wet while crossing a small stream or brook, but it's a different story when hiking the Zion Narrows. This 16-mile trail is along a slot canyon, which means a significant portion of the hike is in a river. The Narrows can seem like a maze... utahtripadvisor.com