Caixaforum, Spain, by Herzog & de Meuron (scroll down for more) Located in a converted 1899 power station in the centre of Madrid, the Caixa Foundation's new cultural space contains exhibition galleries, offices, a restaurant and a theatre. Herzog & de Meuron suspended the structures, then extended the building¹s original brick walls upwards in steel, and collaborated with French botanist Patrick Blanc, who designed a vertical garden on one of the exterior walls.