Chicago
Starchitect Santiago Calatrava's Chicago Spire was supposed to evoke the image of a smoke spiral rising from a campfire along the Chicago River. Due to be completed by 2012, the 150-story tower was meant to be 2,000 feet high, the tallest in the Western Hemisphere and the sixth-highest among all planned skyscrapers. Buyers have already purchased a third of the 1,194 luxury condominiums on offer; Ty Warner, creator of Beanie Baby toys, picked out a $40 million penthouse. But in January, shortly after the foundation was dug, construction faltered; turmoil in financial markets had limited the project's access to credit. Although both Calatrava and local architectural firm Perkins & Will have filed a lien on the project, there are still rays of hope: discussions between unions and the Spire's developer could allow work to recommence soon.
See 10 things to do in Chicago.
See TIME's photos of acclaimed Italian architect Renzo Piano