It’s said that there are no straight lines in Gaudí’s design for Casa Milà (better known as La Pedrera), his apartment building on the city’s chic boulevard, the Passeig de Gràcia. Can that be? Of course some of the later-added windows have straight lines. But look at those poured-concrete curves, that convoluted wrought-iron business along the top balcony. Imagine living here. Dizzying.