Designed by Antoni Gaudi in 1904 as a renovation of a previously built house, Casa Batllo showcases his signature style with a skeletal facade, vibrant colours, and whimsical features, including an arched rooftop reminiscent of the back of a dragon. Located on the Passeig de Gracia, it is part of the Illa de la Discordia (the "Block of Discord"), a row of houses comprised of buildings by noted Modernista architects of Barcelona.