Zion National Park
I went to Zion National Park in 2008 on a trip to hike "The Narrows." The park is really impressive; it is a large valley that progressively gets steeper and more canyonlike as you get farther into it. The Virgin River flows all the way through it, and was the force the carved it over a period of many years.
There are a number of different hikes to do in the park, but the most impressive one is the aformentioned "The Narrows" which is a 16 mile hike down the canyon that ultimately becomes Zion National Park. It is a very interesting place, as the canyon walls are often 1000 feet high, while the width is often 10 feet or less. It is largely done by walking through the river, as there frequently no dry areas to follow.
Another interesting hike is up to Angels Landing, which is quite high and a little bit scary if you are afraid of heights!
I have little doubt that I will be back at some point, Zion is amazing!
