The Next Glass Walkway?

First in the recent trend of glass walkways came the Grand Canyon Skywalk (2007):

[Photo from Grand Canyon National Park]

Then The Ledge at Willis Tower's Skydeck (2009):

[Photo from Skydeck website]

And this year came the Eiffel Tower:

[Photo from Tour Eiffel]

And the Tower Bridge:

[Photo from Tower Bridge Exhibition]

So what will be the next trendy, vertigo-inducing glass walkway attraction?

A logical site would be the Gateway Arch in St. Louis:

[Background image from Together We Roam]

But why not an Amazon warehouse?

[Background photo from Newsweek]

Or even the Oval Office?

[Background photo from White House Museum]

What would you want to see from above through a glass walkway?