Casa Amatller is one of the great Modernista houses on Passeig de Gràcia, standing beside Gaudí's Casa Batlló in the famous Illa de la Discòrdia. Puig i Cadafalch designed it for a chocolate-making family, and the facade is packed with sculptural detail.
It is worth slowing down here rather than treating it as a neighbour of Casa Batlló. Look for the stepped roofline, Gothic references, and the chocolate shop that nods to the family's fortune.