This third version of St. Paul Cathedral (the other two were downtown, on Grant Street) is more than a single building: with its adjoining synod house and rectory and two neighboring schools, it constitutes a medieval grouping unto itself. The Chicago-based architects specialized in Catholic churches of a historicizing character. Here they imitated Cologne Cathedral's twin spires for the exterior, and its fiveaisled nave for the interior. The impressively tall nave, with its pointed-arched arcade and rib vaulting, is imposing rather than alluring; the best element is the immense pipe organ donated by Andrew Carnegie.