As one of the largest architectural festivals in the world, Open House Chicago offers guests access to more than 250 iconic and unique spaces in the city.

Sites include uncommonly seen and “restricted access” areas of theaters, historic mansions, private clubs, sacred spaces, skyscrapers, roof top gardens, professional offices and cultural institutions, among others.

Organized by the Chicago Architecture Center, this free event takes place October 13-14. For a full list of participating sites, please visit

Video produced by Matthew Stanton