An intriguing if not creepy, history lesson on Chicago’s historic underground tunnels.  Urban Ghosts has the story and the eerie photos – go learn something!

In 1899, Illinois Telephone and Telegraph laid telephone cables through Chicago by building a network of underground tunnels. A narrow gauge railway was laid to assist with excavating the tunnels and installing the cables but the system was quickly adapted and used as a means for transporting freight between public stations, basements and elevator shafts.

via Chicago’s Historic Underground Freight Railway Network | Urban Ghosts |.