Salt Mining-Besides salt and other minerals these mines can be cities beneath cities like the one beneath Detroit.

Compressed air- An unusual energy method is to pump compressed air into an old mine. "During the daily peak needs for electricity, air pressure will be bled off through modified combustion turbines to generate electricity. The energy is stored as pressure, but the mine must hold air to store the pressure." Article, two, three, four

The Andersen Library - has been characterized as "geology-friendly;" and indeed, the geology of the site is an integral part of the underground structure. Behind the concrete portal, two enormous caverns, each two stories high and the length of two football fields, lie below a 30 foot layer of limestone plus an additional 30 feet of topsoil, clay and gravel. The solid limestone serves both as the structural roof of the caverns and the foundation for the Andersen Library building above. Minnesota Article,

 Around the USA and elsewhere you'll find deep vaults that have been carved out of the earth. Some were former mines where the resources have dried up. Here you'll find secure storage facilities. Some for private individuals, works of art, government files, compressed air and more. Who knows, there may be one under your feet right now.

Bellamy Cave-2004-This huge cave in Clarksville, Tn. listed in the encyclopedia of Tennessee.

Brady's Bend-Store your cars, campers, boats and much more in this underground former limestone mine. PA

Bussen Quarries-Underground storage in the St Louis area. Average temperature is between 65-72 year round.

Commercial Distribution Center-6,000,000 plus square feet underground with its own rail line. Independence, MO

Corbis goes Underground-Media owned by Bill Gates. Sent 220 feet underground.

Hollywood´s Underground Treasures Bella Online-Have you ever wondered where old movies are stored? Archivists have discovered a unique location northeast of Hutchinson, Kansas, near the Sand Hills Natural Park. The salt mines, 650 feet underground, are the best place to store and preserve old films. Another storage facility for movies is at Iron Mountain, a 220 foot deep limestone mine in western Pennsylvania. Article

Hollywood Vaults-Web site speaking of archiving old movies in super secure, super clean environment. California

 Innerspace Storage Corp. operates a publicly bonded warehouse developed in an underground limestone mine. Situated near Sugar Creek, Mo., a suburb of Kansas City, the mine is in a geological region known as the Bethany limestone ledge.

Interstate Underground Warehouse-Missouri-You can drive right into this underground storage center

Lemp Brewery-The Lemps converted a network of natural limestone caverns into a fantastic underground warehouse with dozens of interconnecting chambers. The family also added a few amenities for the sake of pure entertainment: a "ballroom," a "theater," and a "swimming pool." It's all still down there, and so, reportedly, are the Lemp ghosts

Limestone Caves-There are storage facilities in Pennsylvania as well. This personal website speaks of some of the issues in one such underground complex.

Limestone karst is a unique and complex feature of the Earth's crust. In effect it is a curse that can be turned into blessing. The limestone surface is poor in vegetation, does not support agricultural cultivation, the soils are dry, and irrigation is inefficient. Hidden deep holes drain away water and may swallow animals and humans. Huge underground cavities may cave in without prior warning, taking under whatever might have been above.. Aquifer Storage in Florida

Limestone Living: Converting Mines to Human Space-What to do with an old limestone mine? Fill it -- with people, supplies, offices, and warehouses. In the greater Kansas City area, an estimated 20 million square feet of business and industrial space lies below the ground, squirreled away in space created by the mining of Bethany Falls and Argentine limestone. That accounts for over 10 percent of the business and industrial space in the area.

Love Box-The Wichita-based corrugated box distributor will expand its Kansas City-area operations into a Lexena underground business park. Love Box will become the first tenant of the park, which is being developed by Meritex Inc. of Minneapolis.

Marengo Warehouse-Indiana-One of North America's largest underground storage.

Meritex-Provides more then 6,000,000 square feet of sub-surface warehouse space in various states.

Museum web site The museum has decided to house millions of artifacts in an underground warehouse. The three-floored structure was designed to protect from flooding, wars, earthquakes and more.

National Underground Storage-Record and information storage in an old Pennsylvania mine.

Ozark Mountain-Underground Vault and Storage. Six million square feet-Branson, MO

Shadow Government Keeps Perps Safe Underground-There are many underground facilities throughout the United States which are set up to house those people that are considered 'essential.'

Subterranean Data Storage Co-Perfect place to keep your information. Idaho

Techline-The government is interested in storing natural gas in old abandoned mines. At present there are more then 400 mines which are presently doing this.

Underground Facilities-Independence(Missouri) has two unique subsurface business complexes, Space Center Executive Park and Commercial Distribution Center. One of the benefits of a subsurface location is protection from the elements. Underground facilities have a constant temperature with low humidity resulting in reduced operating costs.

Underground Vaults and Storage-Or also known as the Salt Mine. Storage in Missouri, Kentucky and Kansas. They've been around since 1959.

Underground Warehouses Inc-Carved into the bluffs next to the Mississippi River this Illinois company provides over half a million feet of storage space.

United Fulfillment Solutions-Underground storage in the St. Louis Area.

Wansdyke Security Ltd-100 feet underground. 1 million square feet of secure storage space Wiltshire UK