After walking only a few feet from the St. Gallen train station, you might find yourself drawn—like light being sucked into the eye through the pupil—into a round opening at the entrance to the station’s nineteenth-century Lokremise, or roundhouse. At the edges of the big turntable that once rotated locomotives, six huge glass portals set into a delicate crescent-shaped addition welcome you to the various parts of a new cultural center: a theater, restaurant and bar, cinema, and exhibition/performance space. Hauser & Wirth gallery has already put on a show in this spectacular building,