SubTropolis

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{{short description|American corporation}}

{{Infobox cave

| name = SubTropolis

| photo = Subtropolis.jpg

| photo_caption = SubTropolis

| location = Kansas City, Missouri, United States

| coords = {{coord|39.161213|-94.476242|region:US_type:landmark|format=dms|display=inline,title}}

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File:Subtropolis 02.JPG

SubTropolis is a business complex located inside of a {{convert|55,000,000|ft2|m2|sing=on}}, {{convert|1260|acre|km2|sing=on}} mine in the bluffs north of the Missouri River in Kansas City, Missouri. It was developed by late Kansas City Chiefs owner Lamar Hunt via Hunt Midwest Real Estate Development, Inc., with the trademarked phrase World's Largest Underground Business Complex.

SubTropolis is up to {{convert|160|ft|m}} beneath the surface, dug into the Bethany Falls limestone mine. It has a grid of {{convert|16|ft|m|adj=mid|-high}}, {{convert|40|ft|m|adj=mid|-wide}} tunnels separated by {{convert|25|ft|m|adj=mid|-square}} limestone pillars created by the room and pillar method of hard rock mining.{{Cite web |date=December 15, 2014 |title=What is SubTropolis |url=https://huntmidwest.com/industrial-space-for-lease/what-is-subtropolis/ |access-date=February 20, 2023 |website=Hunt Midwest |language=en-US}} The complex contains almost {{convert|10.5|mi|km}} of illuminated, paved roads and several miles of railroad track.

The mine naturally maintains year-round temperatures between {{convert|65|and|70|F|C}}. The United States Postal Service and the U.S. Environmental Protection Agency lease spaces within SubTropolis, the U.S. Postal Service for its collectible stamp operations and the Environmental Protection Agency for its Region-7 Training and Logistics Center.{{Cite web |url=https://www.bloomberg.com/news/features/2015-02-04/welcome-to-subtropolis-the-business-complex-buried-under-kansas-city |title=Welcome to Subtropolis The Business Complex Buried Under Kansas City |access-date=March 11, 2017 |archive-date=February 16, 2017 |archive-url=https://web.archive.org/web/20170216145933/https://www.bloomberg.com/news/features/2015-02-04/welcome-to-subtropolis-the-business-complex-buried-under-kansas-city |url-status=live }} The National Archives and Records Administration leases space for a Federal Records Center.{{Cite web |url=https://www.archives.gov/frc/kansas-city |title=Kansas City, MO Federal Records Center |access-date=January 11, 2020 |archive-date=January 11, 2020 |archive-url=https://web.archive.org/web/20200111040135/https://www.archives.gov/frc/kansas-city |url-status=live}}

On the surface of the north edge of the complex, Hunt developed the Worlds of Fun and Oceans of Fun amusement park complex. His extensive business dealings in Clay County contributed to the Chiefs establishing a training camp site at Liberty's William Jewell College from 1963 until 1991.

Other facilities exist that are similar to SubTropolis, although not on the same scale, such as the abandoned mine in Butler, Pennsylvania used by Corbis and the Federal Government for secure storage. The room and pillar mining method is used to extract limestone throughout the Midwest, and many companies are looking at ways to utilize the hundreds of millions of square feet created in this manner, such as for mushroom farming and crude oil stockpiling.