This is 99% invisible. I'm Roman Mars.

I'm going to tell you a story first about how a building got designed, a very unusual building in New York, the Citicorp Tower.

When it was built in 1977, Citicorp Center was at 59 stories, the seventh tallest building in the world.

You know, I can still remember the first time I saw at the Citicorp Center.

As you exit the local six subway station at Lexington and 53rd in Midtown Manhattan you're confronted by a sheer

915 foot building face shooting up right from your feet.

That's reporter Joel Werner.

With its gleaming facade of glass and steel and striking 45-degree angle crown, the Citicork

Center is truly one of the most spectacular skyscrapers on a skyline known for its spectacular skyscrapers.

But really, it's the base of the building that takes your breath away.

This massive 59-story skyscraper levitates mid-air, hovering 115 feet above the street corner.

At first glance, the building seems to violate the basic laws of

physics. When you look up you look directly at the underside of the building

corner. It overhangs the sidewalk. I mean we'd expect a column or even the ground. Instead there's nothing. Just thin air.

Of course the building isn't really levitating. It's propped up on stilts, which

join the building at the midpoint of each side. It does not look sturdy. But it's got to be

sturdy, it's got to be safe, but they wouldn't have built it this way, right?

Yeah, well that's a secret about this. they wouldn't have built it this way, right?

Yeah, well, that's a secret about this building,

and it was literally a secret for nearly two decades

after it was built.

The Citicorp Center could very well

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