The Calgary Tower has a see-through glass floor!
525 feet (190 meters) over the city and very freaky. In Calgary, Alberta, Canada.

1. Starting to test the glass. Is it safe? I hope it's thick enough.

2. This is nuts. I can't believe I'm now stepping out on this flimsy piece of glass- probably manufactured at 4:59pm on a Friday.

3. Ok, this feels weird. All my weight is now on the pane of glass.
If it breaks, I'm history.

4. Quick proof of the feat, before fleeing to safety.

5. Tourists standing on the glass. One teenager jumped up and stomped his feet down as hard as he could on the glass. To his fortune, nothing happened.

6. Hovering above the city.

7. View of the Calgary Tower from Downtown.

Stats:

Glass thickness: 2.25" (5.7cm)
Strength: Can withstand 4,000 pounds (1,800kgs)
Distance to ground: 525 feet (160 meters)

Links:

http://www.calgarytower.com/
http://www.turbophoto.com/