**Before writing a scene involving the freight tunnel, writers should familiarize themselves with its physical description. The tunnels are 40 feet underground, humid (but not wet), empty, and in complete darkness.

Lincoln Park Tunnels:
The street map below indicates the actual locations of known freight tunnels in Chicago. For the purpose of our story, we have indicated that the Halsted Street segment of the tunnel extends at least 2.8 miles farther north, towards Lincoln Park (see diagram).



Access Into the Freight Tunnel:
The street map below shows the northern boundary of Lincoln Park (along Diversey Parkway). Our characters will enter Lincoln Park at the intersection of Halsted Street and Diversey Parkway. They will have to be stealthy, because the militarized blockade runs through that area. They will emerge from the tunnel inside Lincoln Park, at the intersection of Halsted Street and Schubert Avenue.

**On both ends, characters will lift a sewer grate in the ground. They'll descend into the sewer. Inside the sewer, there's a hole in the concrete wall. If characters climb through that, they'll be in the freight tunnel.