||Sydney Harbour Bridge, Australia
||Guided climbs through and over the structure to the top of this world famous Bridge, 134 metres above Sydney Harbour.
|Bridge Walk - West Virginia
||New River Gorge Bridge, West Virginia, USA
||Safety-tethered 1½ walk along the 24" wide maintenance catwalk running underneath the third highest vehicle carrying bridge in North America.
|British Airways i360
||The world's tallest moving observation tower, standing at 162 metres high. The i360 (currently being built, Nov 2015) will be the world's first vertical cable car and the world's most slender tower. Visitors will board the 18m wide glass viewing pod at ground level for a 20 min ride to 138m from where they will enjoy 360 degree panoramic views of Brighton and the Sussex coastline.
||Mt Stanserhorn, Switzerland
||Ok, not exactly a "tall building" but the Cabrio is the world's first open-topped cable car, where you can stand outside on the roof, and it looks... well, pretty invigorating!
||The circular observation deck at the top of the 191-metre Calgary Tower has a glass floor.
|Cantilever Swimming Pool
||Holiday Inn hotel, Shanghai Pudong Kangqiao, China
||A glass-floored swimming pool hung out over the edge of this 24-storey hotel in Shanghai. (The official hotel website is very dull, so I've linked to a newspaper article about it.)
||The extraordinary twisted 103-storey/460-metre TV tower (600m with mast) has an elliptical outdoor observation deck at the top and 16 passenger pods that run on a track round the edge of the tower's roof.
||CN Tower, Toronto, Canada
||Tethered walk around the outside of the CN Tower at 356m/1,168ft. And the thrill can start even before you get there because one of the Tower's six glass-fronted elevators now has a glass floor.
||Icefields Parkway, Alberta, Canada
||Another (opened May 2014) circular glass walkway suspended out over nothingness. (It looks a little chillier than the one suspended over the Grand Canyon!) It's almost 1,000 ft to the valley floor (918ft/280m).
|Grand Canyon Skywalk
||Grand Canyon, Arizona
||Probably the best known skywalk in the world right now. The spectacular circular balcony let's people 'walk on air' 4,000ft (1,220m) above the canyon floor.
|Mirador de Abrante
||La Gomera, Spain
||Mirador de Abrante is a restaurant, built in 2013, high up on La Gomera with a cantilevered glass-floored window bay offering a spectacular view of Tenerife in the distance, and the town of Agulo, 650m below.
|One World Observatory
||One World Trade Center, New York
||The One World Observatory at the top of the tallest building in the Western Hemisphere will be opening on 29 May 2015. Maybe not the scariest 'tall building experience' but you can stand on the Sky Portal, a 14ft diameter circle "that will deliver an unforgettable view, using real-time, high-definition footage of the streets below", and the express elevator might challenge your senses (& ears) - 102 floors in 60 secs!
||Willis Tower, Chicago, USA
||The skydeck on the 103rd floor of the Willis Tower (formerly Sears Tower) has four glass boxes called The Ledge cantilevered out 1,353 ft about the ground.
|Sky Experience Adventure
||Crown Regency Hotel Tower, Cebu City, Philippines
||This 38-storey building has two near-death experiences: The Edge Coaster is a slow moving cart with seats that runs along the edge of the top floor. Passengers are strapped in seats that then tip up over the edge. One floor down, the Sky Walk Extreme is a tethered walking experience around an exposed glass floor.
|Skywalk - Auckland
||Skytower, Auckland, New Zealand
||Tethered walk around 1.2 metre-wide walkway with no railings, 192 metres above the ground. There is also a chance to SkyJump attached to a wire, falling for 11 seconds at 85kph to the ground.
|Skywalk - Sydney
||Sydney Tower Eye, Sydney, Australia
||Tethered walk around a balcony at the top of the 268 metre high Sydney Tower (twice the height of Sydney Harbour Bridge) where there's also a glass floored viewing platform.
||Stratosphere Hotel & Casino, Las Vegas, USA
||The Stratosphere Tower is a free-standing part of a hotel & casino complex. It has FOUR terrifying thrill rides/experiences: X-Scream behaves like a runaway roller coaster car that is about to fall over the edge. Insanity dangles carriages over the edge and spins them. SkyJump lets people plummet 855 ft (261 m) attached to a high-speed, descent wire. Big Shot catapults 16 riders from the 921-foot high platform up the Tower's mast to a height of 1,081 feet and down again.
|Titlis Cliff Walk
||Mt Titlis, Engelberg, Switzerland
||Billed as Europe's highest suspension bridge this one metre wide bridge with see-through metal grating opened Dec 2012 (See report) at the top of Mt Titlis (3,000m) in the Swiss Alps.
||The famous bridge is installing glass floors in the upper walkways 42m (138ft) above the Thames. The first was opened Nov 2014, with the second due to open a month later.
|Up At The O2
||O2 Centre, London
||Tethered walk/climb to the top of the O2 Centre (aka The Dome). It looks misleadingly benign, but it's quite steep to begin and accelerated winds over the curve of the dome can make it a slightly wobbly struggle. (They stop operating if the wind speed exeeds 40mph)