CaixaForum Madrid

Opened in February 2008, the long-awaited Caixa Forum cultural center is an architectural tour de force, created by Swiss Pritzker Prize–winning firm Herzog & de Meuron. The shell, an 1899 power station building, was lifted off its base and two futuristic spaces were built above and below, leaving the historic, peaked-roof structure sandwiched in between. A living, vertical garden perpendicular to the building mimics its design at full height. Inside, a trippy five-story stairwell winds down and down. Though the center is meant to be a gallery space, the building itself has garnered much more interest than the preliminary exhibitions.