This building, completed in 1889, launched the careers of architects Dankmar Adler and Louis Sullivan. It originally encompassed a hotel, offices and the Auditorium Theatre. The design of this 4 000-place theatre is an acoustic wonder. After taking on several different functions, it was restored and returned to its initial vocation in the 1960s. The façade is simply delightful, rising out of a block of granite towards smooth limestone, and with Romanesque arcades.