Dubbed the "Grand Central of the Jet Age" by critic Robert A.M. Stern, Saarinen’s curvaceous TWA Terminal was a paean to the romance of flight. The sloped concrete roof recalls two flapping wings, while contours constantly bend and flow into each, creating a fluid collection of terminals, staircases and forms. "We wanted passengers passing through the building to experience a fully designed environment, in which each part arises from another and everything belongs to the same formal world," said Saarinen. After being shuttered for years, the space was turned into a luxury hotel.