Gilberto Zorio’s exhibitions always provide an effective confrontation with space: The artist constructs new works or environments that interact with their architectural envelope. In the large hall of the Museo d’Arte Moderna di Bologna (mambo), Zorio has created the most recent installment of his series of “Towers,” begun in 1976—constructions, made from light, aerated concrete blocks, in the shape of a five-pointed star. Here, the shape of Torre Stella Bologna (Bologna Star Tower), 2009, can be perceived only from the museum’s second-story windows above, which look out from a corridor onto