Located at number 96 on the prestigious Passeig de Gracia avenue, the Casa Mila is listed as a UNESCO World Heritage Site. Built between 1906 and 1910, the architecture of this building with no straight walls is wacky. It represents the pinacle of Modernism with its impressive wavy stone façade and iron balconies. Inside, the brilliant architect has created a fantasy universe, playing on space, shapes, volume, and light. The last floor, composed of a series of 270 brick arches, is home to an exhibition displaying a complete and suggestive vision of Antoni Gaudi and his work, through drawings, photographs, scale models, and video material. You can enjoy a marvellous view over Barcelona from the terrace, where astounding chimneys and air duct openings hidden by 'trencadis' (ceramic mosaics) are true anthropomorphic sculptures.