La Mercè has been celebrated in Barcelona since 1687, in honour of the Virgin of Grace (Mare de Déu de la Mercè) . The Casa Batlló was built in 1877 by Antoni Gaudi, and is one of his most emblematic works. It features practically zero straight lines, and much of the façade is decorated with a colorful mosaic made of broken ceramic tiles. Gaudí’s iconic Casa Batlló was declared a World Heritage Site by UNESCO a decade ago, and this will be celebrated as a part of this year’s ...