This was taken @ Antelope Canyon, Page, Arizona
It is totally magical in this Canyon. The canyon composed of Navajo Sandstone was formed by erosion due to flash flooding during monsoon season.
The floor is sand and these deeply carved walls are I am guessing 30 feet high. You get to walk through this slot canyon which again I am guessing 600 feet long.
I highly recommend a trip here. You have to sign up for a tour but they are totally geared for photographers. Google it and maybe get reviews as to who to choose to take a tour with. We just signed up with one in the town of Page. You will need a tripod for sure. You will be blown away by the beauty, the energy and the majesty of the place. This picture was taken in November 2009.