Located in the heart of the Chicago Financial District, the CH4 data center is located on the 4th floor of an 8-story building on a fiber-linked campus with our CH2 data center. The building was originally constructed for R.R.Donnelley & Sons Printing in 1912, and the Sears Catalog was printed here until 1993. While it was renovated for data center usage in 1999, the building is historically landmarked and protected. The building is 9 miles from downtown Chicago, 25 minutes from Midway International Airport (MDW) and 30 minutes from O’Hare International Airport (ORD).