Most of Antoni Gaudí’s architectural projects were designed from the ground up. Casa Batlló, along the boulevard Passeig de Gràcia, is an exception. The famous architect used an existing building from 1877 as his canvas for Catalan Modernism. Owner Josep Batlló i Casanovas gave Guadí full license to express his creativity. The results feature a colorful mosaic facade, balconies resembling theater masks, a roof with reptile-like scales and a turret claimed to be the lance of Saint George of Lydda. Casa Batlló is a UNESCO World Heritage Site in the Eixample District.