Casa Batllo is one of the two great buildings designed by Antoni Gaudi on Passeig de Gracia, the other being La Pedrera. From the outside the façade of Casa Batllo looks like it has been made from skulls and bones. The "Skulls" are in fact balconies and the "bones" are supporting pillars. Gaudi used colours and shapes found in marine life as inspiration for his creativity in this building .