Have you ever walked by a building and thought, "I wish I could see what's inside?" Now you can. The Chicago Architecture Foundation’s Open House Chicago is a free public festival that offers behind-the-scenes access to more than 200 buildings across Chicago.  Explore the hidden gems and architectural treasures of Chicago’s diverse neighborhoods—all for FREE.

The event will take place the 14th and 15th at 9:00 am. The printed event guide will be available in the 2012 issue of the Chicago Tribune. It can also be found at participating locations and at Chicago Architecture Foundation headquarters. 
More info here.