The two great architectural works of Lluís Domènech i Montaner, the Palau de la Música Catalana and the Hospital de Sant Pau were declared a World Heritage Site in 1997, considering that both are masterpieces of the imaginative and exuberant Art Nouveau that flourished at the beginning of 20th century of Barcelona. These two magnificent buildings, together with the works of Antoni Gaudí, are the only ones in Barcelona that show off this remarkable honour.