Antelope Canyon, Arizona- After you squeeze into the canyon you're met with a metal ladder to help you get to the bottom. Before the ladder was installed travelers had to rappel to the bottom, and there wouldn't be any way to get out of the canyon at the opposite end without a ladder. Photo by Travis Burke.
Spooky Gulch, south of Escalante, Utah. Travelers who are claustrophobic may want to avoid hiking Spooky Gulch. Passageways are so narrow in some places, hikers have to squeeze through sideways. It also can be quite dark on the canyon bottom. This canyon walk is 5 km (3.2 miles) roundtrip. Those who don’t want to go back the way they came can climb the canyon walls or continue on through Peek-a-boo Gulch, another beautiful slot canyon.