The Subway route in Zion National Park is known all across the world, and frequently seen on postcards, posters, and various other trinkets sold in and around Zion. The Subway gets its name from a section of the canyon that narrows and is cylindrical in shape, very similar to....you guessed it, a Subway! While the subway like feature of the canyon is most recognized, the route is a wild and wet ride down 8 miles of canyon. There are approximately 5 rappels through waterfalls and into ice cold pools. There are also several mandatory swims that one has to go through. This is one of the greatest adventures in the USA, and I would recommend it to anyone. Be sure to plan ahead, only 50 people are allowed in the canyon per day.