David Mcnew / Getty Images
VIP's and members of the media and the Hualapai tribe preview the Skywalk, billed as the first-ever cantilever-shaped glass walkway extending 70 feet from the western Grand Canyon's rim more than 4,000 feet above the Colorado River, on March 20, 2007 on the Hualapai Reservation at Grand Canyon, Ariz. The $40 million glass and steel platform was opened to the public later that month.
C.H. / Innovation Norway
Architects Todd Saundersand Tommie Wilhelmsen were commissioned to design a scenic rest-stop 2,000 feet above Norway's Aurland fjord and came up with this beauty, winning the first prize in Norwegian tourist routes competition. The outermost end of the horizontal platform -- which curves to form the structure's support -- is closed off by a sheet of glass, offering an incredible view towards the ground.
The Gardens of Trauttmansdorff Castle
Within the gardens of Trauttmansdorff castle in Italy, you'll find this charming Matteo Thun-designed steel platform poking out through the trees, its name (meaning "the binoculars") coming from the shape of the platform's small roof and the view of the surrounding landscape.
Juan Mabromata / AFP - Getty Images
While the Iguazu Falls themselves are magnificent, their setting in a huge subtropical nature reserve makes visiting even more enjoyable. To fully appreciate their size and splendor, it's worthwhile viewing the falls, which border Argentina and Brazil, from the skywalk. The viewing platform is so close you are instantly drenched by spray and deafened by the roar of water plunging over an 80-meter cliff.
Planai-Hochwurzen Bahnen / Schladming-Dachstein
Nicknamed the "balcony of the alps," the Dachstein Sky Walk is formally enthroned at 2,700-meters above sea-level, high up on the 250-meter vertical rock face of the Hunerkogel. A 360-degree panorama allows the visitor a view of Slovenia in the south to the Czech Republic in the north.
Greg Wood / AFP - Getty Images
Visitors standing on a cantilever at the Illawarra Fly Treetop Walk, shown here on June 8, 2009, can see rainforest on the left and the coastline, center, of the Illawarra region, south of Sydney, Australia. The Illawarra region is given its special character with the way the escarpment meets the sea with visitors to the Treetop Walk given a unique view from high above the trees.
Scott Olson / Getty Images
Visitors check out the view from the Ledge, a 1,353-foot-high glass cube that juts out from the 103rd floor Skydeck of Chicago's Willis Tower (formerly known as the Sears Tower), on July 1, 2009.
Wolfgang Zajc / Österreich Werbung
Top of Tyrol by Aste architecture is a viewing platform located 3,000-meters above sea level at the Stubai Glacier in Tyrol, Austria. Weathering steel was used in the construction of this structure to account for the extreme weather conditions so you can stand 9 meters away from the mountain with a perfect view of Stubai glacier.
House on the Rock
The House on the Rock, originally opened in 1959, is a complex of architecturally unique rooms, streets, gardens and shops designed by Alex Jordan, Jr. It is located in Spring Green, Wis., and is a regional tourist attraction. The Infinity Room at the House extends several hundred feet over the valley, without supports underneath, and is lined with more than 3,000 handmade windows.
Christof Sonderegger / Swiss-image.ch
Switzerland's landscape promontory is a suspended viewing platform designed by Paolo Bürgi as part of the Cardada project, a revitalization of the Cardada mountain that is expected to finish in 2010. The passageway is made of steel and titanium leads to the lookout platform with a view of Lago Maggiore. It also includes symbols in the paving with accompanying texts in the railing to provide references to history and literature.