Columbia has an extensive tunnel system connecting most buildings on campus and acting as conduits for steam, electricity, telecommunications, and other infrastructure. The tunnels are a mysterious, foreboding place fully explored only by legendary figures in campus history. They are rumored to be where unspeakable acts of pure horror are committed.
- See main article at History of the tunnels
List of tunnels
- See main article at List of tunnels
Old maps, from the 1950s, are accessible easily from the Columbiana Library. They are still roughly accurate. If you bug the reference librarian enough she might bring over the newest editions of the grounds maps. These new maps unfortunately can't be posted online due to copyright restrictions.
The map at the top of this article was created by former Columbia student Mike Schiraldi and released under the GFDL. It was created in 1999 so it's somewhat out of date, and is incomplete. The purple areas, marked "rumored," are just that; they almost certainly don't exist. As described in the map's legend, different colors are used to indicate different types of tunnel and levels of certainty:
- Green lines indicate areas that are not only known to exist but also places that the Columbia administration openly allows students and staff to be. For example, the underground connection between Hartley and Wallach halls.
- Yellow lines indicate areas that are known to exist but considered off-limits to all but Columbia's maintenance workers.
- Purple lines indicate rumored connections that have not been verified. In particular, there is almost certainly no tunnel under Broadway or along College Walk.
Famous tunnel explorers
- Benoit - a famous tunnel explorer who still answers questions about and leads tours of the system
- Ken Hechtman - a student whose group ADHOC wrought havoc in the tunnels in the 1980s and subsequently was expelled for stealing uranium from the Pupin basement
- "Brian" - Current (2020) CU senior who can show students around. Message email@example.com. Anonymous emails may be ignored. features.columbiaspectator.com/eye/2016/04/13/unearthing-the-underground
- Restricted Access Photographs
- columbiatunnels.org - inactive
- Forbidden Tunnels Guard CU History - Columbia Spectator article
-  - FREE THE TUNNELS