Architect Christoph Ingenhoven describes Düsseldorf’s Schauspielhaus as “light, as though floating in the air.” The public theater, inaugurated in 1970, sits between the Gustaf-Gründgens-Platz and an expansive urban park, the Hofgarten. Enclosed in white serpentine walls and raised off the ground on piloti, its organic curves providing a strong contrast to the Miesian regularity of its immediate neighbor, the Dreischeibenhaus—a 25-story office tower completed a decade earlier. “I’ve admired the Schauspielhaus forever,” says Ingenhoven, who grew up in this northwest German city and whose eponymous practice is based there.