The Grand Canyon Skywalk is a transparent horseshoe-shaped cantilever bridge and tourist attraction in Arizona near the Colorado River on the edge of a side canyon in the Grand Canyon West area of the main canyon. USGS topographic maps show the elevation at the Skywalk's location as 4,770 ft (1,450 m) and the elevation of the Colorado River in the base of the canyon as 1,160 ft (350 m), and they show that the height of the precisely vertical drop directly under the skywalk is between 500 ft (150 m) and 800 ft (240 m).

“BASE jumping, also sometimes written as B.A.S.E jumping, is an activity that employs an initially packed parachute to jump from fixed objects. “B.A.S.E.” is an acronym that stands for four categories of fixed objects from which one can jump: buildings, antennas, spans (bridges), and earth (cliffs)”. – Wikipedia

Photo: Felix Baumgartner, world-renowned B.A.S.E jumper, is pictured in this undated handout photo. Baumgartner will attempt the first unpowered crossing of the strait between England and France. (Photo by Red Bull via Getty Images)

Guests spend the night in the beach bar so called club of the visionairs in the early morning hours of August 21, 2011 in Berlin, Germany. Berlin, which is among Europe's most popular travel destinations, is crisscrossed with canals and rivers over which lead a total of 564 bridges. The city's ample access to water has encouraged many bar and restaurant owners to create beach atmosphere as a growing summer day- and nightlife institution. (Photo by Carsten Koall/Getty Images)

Artist Elizabeth Thompson poses next to her Blu-tack Spider sculpture at London Zoo on October 25, 2007 in London, England. The sculpture, known as “Blu-ey”, is a model of a common house spider and is completely made out of blu-tack. It is on show at BUGS! at ZSL London Zoo. The sculpture is made from around four thousand packets of Blu-tack and weighs over 200kg. (Photo by Chris Jackson/Getty Images)

Characters from Star Wars pose for a photocall to promote the release of Star Wars: Episode 1 – The Phantom Menace 3D at The London Eye on February 8, 2012 in London, England. (Photo by Dave J. Hogan/Getty Images)

Keira Knightley attends the premiere for “A Dangerous Method” at The 55th BFI London Film Festival at The Odeon West End on October 24, 2011 in London, United Kingdom. (Photo by Dave Hogan/Getty Images)

Workers lay railway track in a tunnel of the Crossrail project in Stepney, east London, Britain, November 16, 2016. Crossrail, which is Europe's largest construction project, is a railway link which will connect outlying areas to the east and west of London with tunnels under the centre of the capital. (Photo by Stefan Wermuth/Reuters)

The Photo London Master of Photography award is given annually to a leading contemporary photographer. A special exhibition shows new and rarely seen images from Burtynsky’s portfolio. Here: Morenci Mine #2, Clifton, Arizona, USA, 2012. (Photo by Edward Burtynsky/Metivier Gallery, Toronto/Flowers Gallery, London)