Santiago Calatrava was commissioned to design several of the venues for the 2004 Summer Olympics in Athens, Greece. The works, officially known as the Athens Olympic Sports Complex (OAKA) include the roof of the Olympic Stadium, which has gained certain noteriaty in that it was very nearly not completed in time for the games, the velodrome, and the agora.
Ultimately, the Greeks were able to complete all but one major project; the roof of the Swimming complex was scrapped in the Spring of 2004 due to the fact that it would not have been completed in time for the games.
As both engineer and architect, Calatrava has designed several structures that are so dynamic that many conservative engineers proclaimed that the structures could not succeed. Though they did prove challenging, clearly they have also proven to be successful.