Grand Canyon Skywalk

Afraid of heights? You might tread carefully, then, if you visit Grand Canyon West, a tourist destination whose main attraction is The Skywalk. The cantilevered walkway, which is made its media debut Tuesday, is a mere 4,000 feet above the bottom of the canyon. It opens to the public on March 28.

Astronaut Buzz Aldrin, the second man to walk on the moon, was one of the first to walk out onto the structure.

March 21, 2007 8:03 AM PDT

Photo by: Robyn Beck/AFP/Getty Images