Interesting

The Congress Plaza Hotel is located on South Michigan Avenue across from Grant Park in Chicago at 520 South Michigan Avenue. Its eleven story edifice was originally designed by architect Clinton J. Warren as an annex to the Auditorium Theater across the street. The two buildings were linked by a marble-lined underground passage called Peacock Alley. After opening for business in 1893, for the World's Columbian Exposition, the hotel underwent two major expansions and renovations, first in 1902 and then again in 1907 which brought the total complex up to 1 million square feet (93,000 m2). The design and construction of these two additions were overseen by the firm of Holabird & Roche. The hotel now features 871 guest rooms and suites.