The Guggenheim Museum Bilbao is a museum of modern and contemporary art designed by Canadian-American architect Frank Gehry, and located in Bilbao, Basque Country, Spain. One of the most admired works of contemporary architecture, the building has been hailed as a "signal moment in the architectural culture", because it represents "one of those rare moments when critics, academics, and the general public were all completely united about something", according to architectural critic Paul Goldberger.

The museum was the building most frequently named as one of the most important works completed since 1980 in the 2010 World Architecture Survey among architecture experts. The so-called "Bilbao effect" refers to how the museum transformed the city. The term, however, has also been employed by critics who have denounced the museum as a symbol of gentrification and cultural imperialism. The Wall Street Journal suggested that the Bilbao effect should be called the Bilbao anomaly, "for the iconic chemistry between the design of a building, its image and the public turns out to be rather rare." In an interview with The Guardian, Gehry says of the Bilbao effect, “it’s bullshit... I spent a lot of time making the building relate to the 19th century street module, and then it was on the river, with the history of the river, the sea, the boats coming up the channel. It was a boat.” [Wikipedia]