La Casa Amatller (Amatller's House) is a modernist building located on one of the main streets of Barcelona, Passeig de Gracia. It was designed by the Catalan architect Joseph Puig i Cadafash and is situated near two other famous buildings: Casa Batlló, a house designed by the Catalan architect Antonio Gaudi, and Casa Lleo Morera, a modernist house designed by Lluís Domènech i Muntaner. Together, these buildings are known as the 'apple of discord' ("manzana de la discordia" in Spanish).
La Casa Amatller was commissioned by the Catalan chocolate entrepreneur Antoni Amatller, whose idea was to restore the facade from 1875 and make the building functional. The project to restore the building was based on the idea to combine the Catalan Gothic style with the European medieval Gothic, especially the one characterizing many Dutch buildings. Furthermore, the building's style integrates the style of the modernist era.
The most interesting part of the building is the main façade with its stunning roof resembling a chocolate bar. Together with the sculptural groups of Saint George and the dragon, wrought iron platforms and balconies as well as two asymmetric entries: one intended for tenants and the other one for coaches, they make the building not only visually appealing, but also colour-coordinated with the neighbouring buildings. Through the façade, one may access the patio, the staircase leading to various rooms, and the flamboyant main apartment. Inside the building, one can admire the ostentatious ornaments characteristic of the Catalan bourgeoisie of that time.
Since 1960 the house has been the property of the Amatller Institute of Spanish Art, which was founded by Antoni Amatller's descendants. On 9 January 1976 it was declared a national monument.