La Pedrera's rippling stone front hangs from iron beams instead of holding the building up. No wall inside carries any weight either, so the rooms of a flat can be moved or knocked through at will. Gaudí built it between 1906 and 1912 for Pere Milà and Roser Segimon, and the city, unimpressed by the raw quarried look, named it after a stone pit. The blocks were hoisted up and carved in place on the scaffolding so the curve would run unbroken; Josep Maria Jujol twisted the balcony rails out of scrap iron, no two alike. Cars were designed in from the start: the basement was drawn as a garage, among the first under any Barcelona apartment block.
What you climb for is the roof. The terrace rises and falls in steps, and the chimneys and ventilation towers that come up through it are each twisted into a different shape and turned a different way, so they stand around you like helmeted figures. Below them the attic runs on 270 brick arches, and the long room they carry was once where the tenants dried their washing. It never became only a museum: people still live and work behind those windows, and the stone shifts from grey to honey as the day turns.