On the surface at least, Casa Batlló is Gaudí at his most imaginative, despite it being a renovation of what was an existing building. Buy tickets in advance – after La Sagrada Familia this is about the most popular tourist attraction in town and there are always queues.
Don’t forget to check out Casa Amatller and Casa Lleó Morera adjacent – part of the “mansana de la discòrdia” or block of discord of Barcelona, named because of the sharply contrasting architectural styles.