Antoni Gaudí never lived to see Casa Milà receive electricity throughout its apartments — the building was wired floor by floor between 1910 and 1912, and by the time the last tenant moved into the attic quarters in 1912, Gaudí had already shifted his entire focus to the Sagrada Família. The structure at Passeig de Gràcia 92 was commissioned by Pere Milà i Camps and his wife Roser Segimon, who wanted a rental property that would also serve as their residence. Gaudí delivered a six-story apartment block with an undulating stone facade, wrought-iron balconies that resemble seaweed, and a rooftop populated by chimneys shaped like medieval helmets. The building earned the nickname La Pedrera — the stone quarry — from neighbors who found its wave-like facade unsettling. It remains the only twentieth-century civil building in Barcelona inscribed on UNESCO's World Heritage list. Today, casa mila night tour tickets offer access to the rooftop terrace after sunset, when the sculptural chimneys cast long shadows and the city's grid spreads out in a carpet of amber light. The evening visit format was introduced to reduce daytime crowding and to showcase the building's illuminated profile, which Gaudí himself never witnessed. The rooftop's 30 chimneys and two ventilation towers are clad in broken ceramic and glass fragments — trencadís — and their silhouettes shift as visitors move between them. The night experience includes the attic space, where 270 catenary arches support the roof without a single load-bearing wall, and the Espai Gaudí exhibition, which documents the architect's structural innovations through models and drawings. Access to one of the restored apartments on the fourth floor shows how Barcelona's bourgeoisie lived in 1910, with period furniture and Modernista decorative arts. The building's engineering was radical for its time. Gaudí used a steel frame to support the facade, freeing the stone from structural duty and allowing him to carve the wavelike surface without compromising stability. The courtyards — one circular, one oval — draw light and air into the interior, and the basement garage was among the first in Barcelona designed for automobiles. Casa mila night tour tickets tours typically include audio guides narrated by architects and historians, and the rooftop visit concludes with views toward Tibidabo and the Collserola hills. The site opens at 09:00 daily, but evening slots between 20:00 and closure offer cooler temperatures and fewer groups. Gaudí's final secular commission stands as a bridge between nineteenth-century historicism and twentieth-century abstraction, and the after-dark rooftop remains one of the clearest demonstrations of his ability to merge structure with sculpture.