# Most/deepest publically accessible underground floors in a building? **URL:** \ **Category:** Factual Questions\ **Created:** [February 16, 2012, 12:57am UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985 "2012-02-16T00:57:24Z")\ **Posts on this page:** 12\ **Page:** 2
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [July 16, 2014, 5:28pm UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985/21 "2014-07-16T17:28:58Z")
> [@BobArrgh](#): > > I’m not sure if this meets the criteria of “publicly accessible”, but the Kansas City SubTropolis is an immense underground storage facility. > > [SubTropolis, U.S.A. - The Atlantic](http://www.theatlantic.com/magazine/archive/2010/05/subtropolis-usa/8033/) That’s the first thing I thought of, too, but there isn’t anyplace where it is accessed vertically, so the fact that there is ground above it is not relevant. All entry and exit are at grade. ---
**Author:** ![Tom\_Tildrum](https://avatars.discourse-cdn.com/v4/letter/t/e95f7d/32.png) [@Tom\_Tildrum](https://boards.straightdope.com/u/Tom_Tildrum)\ **Post date:** [July 16, 2014, 5:37pm UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985/22 "2014-07-16T17:37:01Z")
The US Office of Personnel Management runs a large, active [office](http://www.washingtonpost.com/sf/national/2014/03/22/sinkhole-of-bureaucracy/) in an abandoned mine 230 feet below ground. ---
**Author:** ![El\_Kabong](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/el_kabong/32/496_2.png) [@El\_Kabong](https://boards.straightdope.com/u/El_Kabong)\ **Post date:** [July 16, 2014, 6:18pm UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985/23 "2014-07-16T18:18:09Z")
Although not a building per se, the underground lunchroom at Carlsbad Caverns in New Mexico is quoted as 754 feet below surface. Elevators connect it to the Visitor Center above, so that may be close enough for government work. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [July 17, 2014, 6:40pm UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985/24 "2014-07-17T18:40:34Z")
The [Washington Park MAX Station](http://en.wikipedia.org/wiki/Washington_Park_(MAX_station)) near the Portland Zoo is 260 ft underground. The Wikipedia article says it’s the deepest station in the US but not the world, so follow the links for deeper places. Definitely publicly accessible. ---
**Author:** ![HipGnosis](https://avatars.discourse-cdn.com/v4/letter/h/76d3ee/32.png) [@HipGnosis](https://boards.straightdope.com/u/HipGnosis)\ **Post date:** [July 17, 2014, 7:42pm UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985/25 "2014-07-17T19:42:51Z")
> [@jtur88](#): > > That’s the first thing I thought of, too, but there isn’t anyplace where it is accessed vertically, so the fact that there is ground above it is not relevant. All entry and exit are at grade. Where are you getting the requirement for vertical access?? ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [July 18, 2014, 6:27am UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985/26 "2014-07-18T06:27:38Z")
the Minnesota Department of Natural Resources has a State Park located around the Soudan Underground Mine. Public tours of the mine and the University’s High Energy Physics Lab located deep in the mine are available. The deepest part of the mine is 2,341 feet (713.5 m) below the surface. ---
**Author:** ![gracer](https://avatars.discourse-cdn.com/v4/letter/g/8e7dd6/32.png) [@gracer](https://boards.straightdope.com/u/gracer)\ **Post date:** [July 18, 2014, 7:58am UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985/27 "2014-07-18T07:58:58Z")
Edinburgh has a whole underground city made up of vaults connected by tunnels. I don’t know how many floors down at most, but I remember one pub you had to just spiral down and down endlessly to get to. As the thread already mentions 10 floors down this probably isn’t a winner, but it should win “most spooky”, and perhaps “oldest”. 🙂 ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [July 18, 2014, 1:28pm UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985/28 "2014-07-18T13:28:43Z")
I used to work in [T](http://www.loc.gov/pictures/item/oh1943/)-[Building](http://www.colliers.com/-/media/Images/Properties/ide/f/2/2/4c636edf46b49b291818daea434e/TheMound.pdf.pdf?la=en-US) at the DoE’s Mound facility. It’s five stories underground, built with an incredible amount of concrete: the roof is 15 feet thick, the walls are 16 feet thick, and the slab is 8 feet thick. ---
**Author:** ![Ann\_Hedonia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ann_hedonia/32/319_2.png) [@Ann\_Hedonia](https://boards.straightdope.com/u/Ann_Hedonia)\ **Post date:** [July 18, 2014, 1:38pm UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985/29 "2014-07-18T13:38:26Z")
The gold vault at the New York Federal Reserve is 5 stories below ground level ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [July 18, 2014, 4:31pm UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985/30 "2014-07-18T16:31:30Z")
> [@Ann\_Hedonia](#): > > The gold vault at the New York Federal Reserve is 5 stories below ground level Publicly accessible? ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [July 18, 2014, 6:46pm UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985/31 "2014-07-18T18:46:01Z")
> [@robert\_columbia](#): > > I know that there is a publicly accessible complex underneath the National Mall in DC that includes the S. Dillon Ripley center and a few other buildings, and I believe that goes down to at least the 3rd Basement (B3), and there are several exhibits at that level. I once had an office there. We called it "The Basement of the Nation’s Attic.😃 ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [July 18, 2014, 8:26pm UTC](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985/32 "2014-07-18T20:26:43Z")
> [@ftg](#): > > > [@Ann\_Hedonia](#): > > > > The gold vault at the New York Federal Reserve is 5 stories below ground level > > Publicly accessible? [Yes](http://www.newyorkfed.org/aboutthefed/visiting.html). “Guided museum tours also include a trip to the New York Fed’s gold vault.” [Previous page](https://boards.straightdope.com/t/most-deepest-publically-accessible-underground-floors-in-a-building/612985.md?page=1)