"It’s one of the most recognizable facades on Passeig de Gràcia: amodernist fantasy of undulating stone, brightly colored mosaics, and stained glass—one that could only come from the mind of famed Catalan architect Antoni Gaudí. Designed in 1904 as a home for local industrialist Josep Batlló, the building pays homage to the legendary tale of Saint George and the Dragon. The balconies are reminiscent of skulls, and exterior columns look like bones—recalling the dragon’s human victims—while the roof’s arched shape and scale-like tiles mimic the dragon itself. The interior is just as fantastical, all sinuous lines and curving forms. To avoid the crush, try going first thing on a weekday morning, or shell out a bit extra for a Fast Pass timed ticket online (28.5 euros, or about $37—5 euros more than regular admission)."