Former astronaut Buzz Aldrin joined Indian leaders Tuesday to open a glass-bottomed walkway that juts over the edge of the Grand Canyon.

Aldrin was among the first to walk across the horseshoe-shaped skywalk Tuesday in the remote Hualapai Indian reservation in Arizona. It extends 21 meters over the edge of the Grand Canyon, allowing visitors to view straight down to the canyon floor more than 1,200 meters below.

The $30-million skywalk was funded by a Las Vegas developer. The Hualapai Indians hope it will increase tourism in the area. They plan to charge $25 to walk on it.

Some environmentalists have criticized turning the canyon into a tourist area. Some Hualapai elders have also spoken against building near burial sites.

Some information for this report was provided by AFP, AP and Reuters.