Witness construction of Spain's strangest skyscraper: the 700-foot tall Torre Espacio, a.k.a., the Space Tower. It's the only skyscraper in the world where every single floor plan is completely different - a design feature dictated by the crazy, spiraling shape of the structure. Support columns tilt at weird angles, and the concrete forms used to layout each floor change as the building rises.

Videodisc release of the television program 'Extreme engineering" produced for the Discovery Channel.