Heading back to Zion National Park, The Subway is a favorite among experienced canyoneers and adventurous photographers. Sculpted by the Left Fork of North Creek, this section has a unique tunnel shape that resembles a subway tube. The rock floor of the slot canyon is riddled with potholes from the water that rushes through, and they are usually filled with icy cold water. This lends not only a beautiful mix of colors to the slot canyon but also a compelling dance of light as it reflects and refracts. Plus, you'll find frogs, dragonflies and other water-dwelling critters. Because of the difficulty level of The Subway, which requires skills with ropes and repelling (and the fact that you have to swim through at least three pools of cold water), this is one canyon that most of us will only enjoy through photos.