London's most daring tourists recently got a chance to be the first to experience a new glass floor on the upper walkways of the iconic Tower Bridge. The upper walkways were originally designed to allow pedestrians to cross while the bridge was raised. Now the new glass floor offers some unique and heart-racing views of the bridge and river below. If other examples of the popularity of thrilling pedestrian walkways are any indication, it's sure to draw crowds.

Designed by Sir Horace Jones, the combined bascule and suspension bridge was opened by the Prince of Wales in 1894. According to the London Evening Standard:

It takes nerve to walk across the toughened glass walkway, which is 11m long, 1.8m wide, and made up of six panels, which are 68mm thick and each weigh approximately 530kg. But the new perspective on London’s river is undeniably spectacular.

The walkway, dubbed “the wow project’ while it was under construction, was evolved in consultation with English Heritage, after an initial plan for a new glass floor between the two walkways was rejected.

The floor exposes the steel lattice work of the bridge itself. Some steel panels were removed to clear the view, with the proviso that they could be restored.

Have a look for yourself in this video.

Earlier this fall, Switzerland's Glacier 3000 opened the first and only suspension bridge to connect two mountain peaks. You can check that one out in this video, and see more spectacular foot bridges in the slideshow.