La Pedrera (Casa Mila)

Casa Milà is Gaudí's final apartment building and his most radical departure from straight lines - the entire facade ripples like water, with wrought-iron balconies that look like tangled seaweed. You'll explore a recreated 1910 bourgeois apartment (complete with period furniture and servant quarters), the undulating attic with its cathedral-like arches, and the rooftop where 30 sculptural chimneys rise like armored sentinels. The audio guide explains Gaudí's engineering genius, from the innovative ventilation system to the load-bearing walls that eliminated the need for interior supports.

The visit flows upward through increasingly surreal spaces. The apartment feels lived-in rather than museum-sterile, with Art Nouveau details in every door handle and light fixture. The attic's white parabolic arches create an almost spiritual atmosphere - this is where Gaudí's structural innovations become pure art. The rooftop finale delivers Barcelona's best 360-degree views, framed by those otherworldly chimneys that change personality depending on the light.

At €25 for adults, it's expensive but less crowded than Casa Batlló and more architecturally significant. Skip the €7 audio guide upgrade - the free version covers everything important. The gift shop is overpriced tourist trap, but the rooftop cafe serves decent coffee with unbeatable views. Summer evening visits (€34) include cava and projection mapping on the chimneys - genuinely magical if you don't mind the premium.