Rainbow Bridge National Monument sits within Lake Powell on the Utah side, and although is one of the largest natural bridges in the world, this national monument is one of the smallest managed by the National Park Service. Rainbow Bridge itself stands 290 ft tall from the base to the top of the arch, and is 275 ft across, making it nearly as tall as the Statue of Liberty. The most popular way to access Rainbow Bridge is via boat on Lake Powell. You can take a boat tour to this area, then walk 1 mile to the bridge. This is a very expensive option, but again, the most popular. If you are looking for more of an adventure, plan to backpack the 15 mile trail instead.