Santiago Calatrava is one of the world’s most celebrated architects. He has designed extravagant buildings, bridges, and structures all over the world. I remember thinking, This is so cool!, when I saw his exhibition at the Metropolitan Museum of Art in New York City in 2005.

I just heard about The Chicago Spire, one of Calatrava’s works in progress being built in Chicago, IL (USA, Earth). The project broke ground this past June and the project is expected to be completed by 2010.

At its completion, The Chicago Spire is set to be North America’s tallest structure and the tallest all-residential building in the world. The structure will be 2000-ft tall with about 150 stories housing about 1193 condominiums, each one rotated exactly 2.44 degrees from the one below it to complete the building’s “rotating” design. Pretty impressive. The building is being developed by Shelbourne Development Group (you can see some more photos of the interior and exterior there).

And yes, The Chicago Spire will surpass the height of the ugly-ass Freedom Tower that will sit at the base of the former World Trade Center location.

If you’re wondering where you might have seen something like The Chicago Spire before, maybe you’re thinking about the Turning Torso in Sweden — also designed by Santiago Calatrava.

Check out the video below of Santiago Calatrava talking about the building’s concept and development.

Some interior renderings of what the condominiums might look like when completed inside…