Sometimes a single building can transform the image of a city. Despite the traumas, tantrums and cost overruns associated with its construction, the Sydney Opera House quickly came to symbolize a commitment to creativity and modernity. No longer a colonial outpost at the bottom of the world, Sydney was suddenly perceived as a dynamic Pacific Rim metropolis. The rusting steel town of Bilbao was similarly given an unexpected new identity by the titanium whorls of Frank Gehry’s Guggenheim museum.