Just outside of Page, Arizona, just before you get to the power plant there, as an absolutely beautiful slot canyon on Navaho Tribal lands. Basically, just south of town, turn east on Hwy 98. Then just a little less than 5 miles on that road and you come to Antelope Canyon. On the right side on the road is Upper Antelope Canyon and on the left is Lower Antelope Canyon. The upper canyon is probably the more famous, especially for a spot where a beam of light shines down during mid-day. It is also much easier to walk through as it is wider, much more level, and about 1/4 mile long. The lower canyon is at least twice as long, and you descend many ladders, and finally come up some at the end, before walking back to the entrance along the surface.
I have two galleries here. The first is from 2003 when we visited Upper Antelope Canyon first thing in the morning to avoid the crowds. The second was in 2013 when we visited Lower Antelope Canyon. The are both awesome!