This hotel was built in 1893 as the Auditorium Annex. The Clinton J. Warren design in limestone mimicked its namesake, the Auditorium Building, with arcaded windows and a third-floor balcony. Polygonal bays rib the facade, which was extended to the south in 1902 and 1907 by Holabird & Roche. Step inside the Congress Parkway lobby to see the lovely mosaic tile arches.