The cleaning service staff at Chicago's Sears Tower now have a new glass surface to clean: floors.

The world is now obsessed with everything superlatives - tallest, largest, most iconic - but none of the world's most iconic skyscrapers offers glass-floored balconies, suspended 1,353 feet (412 meters) in the air as an attraction.

The balcony is only 4 feet away from the Sears Tower's 103rd floor Skydeck, and if you dare enough to look straight down, you know how it feels like to be a Spiderman.

The balcony, nicknamed 'The Ledge", opened for public yesterday.  

Source: Sears Towers [AP via Yahoo!News]