Art and architecture are the treasures of this great city. See the Paseo de Gracia, the Champs-Elysees of Barcelona; the lush hilltop retreat of Montujïc with its Olympic Stadium; and a panorama of Gothic and modern architectural marvels. Art nouveau architect Antoni Gaudí left an indelible mark on Barcelona with his moderniste style. Experience his most important works including the fascinating and unfinished La Sagrada Familía, dripping in symbolism, and the lofty Parc Güell, with its mosaic serpentine benches and commanding view.