Hidden city

Kansas City is famous for many things: the Super Bowl-winning Kansas City Chiefs, delicious barbecue, Russell Stover chocolates, and the Nelson-Atkins Museum of Art, among other distinctions. But the city also boasts a lesser-known title: home to the world’s largest underground business complex, SubTropolis.

Located 8 miles northeast of Kansas City’s downtown, SubTropolis is nestled 150 feet below ground in a former Bethany Falls limestone mine. The 55 million-square-foot mine produced the limestone used in building much of Kansas City. When mining was complete, a vast space with a network of 25-foot square pillars remained. 

Enter Lamar Hunt, the legendary founder of the Kansas City Chiefs, who is credited with naming the Super Bowl. The Chiefs’ early success made Hunt eager to invest further in Kansas City and, with his background in geology, Hunt soon connected with Underground Storage Inc., which had started to transform former limestone mine space into business facilities for companies like Ford, Russell Stover, and Pillsbury in the 1960s.

Fast-forward to today, SubTropolis, owned by Hunt Midwest, currently operates in 8 million square feet with more than 6 million square feet available for expansion. It holds a roster of 60 tenants and 3,000 employees. Tenants include the National Archives, the U.S. Postal Service, the Environmental Protection Agency, automotive companies, data and cloud storage providers, and Underground Vaults and Storage, Inc., which houses film and television archives. 

Mike Bell

“We have more than 10 miles of paved roadways, plenty of light, and it’s dry and secure,” says Mike Bell, senior vice president of industrial for Hunt Midwest. “It’s like our own city.” 

70 degrees and overcast 

The nature of the location and its stable climate make SubTropolis an ideal place for many companies to operate and grow. 

Tenants like the National Archives, which require steady temperature and humidity levels to preserve sensitive documents or materials, find the underground facility particularly advantageous. 

“Any business with a security requirement or that needs a constant environment is a perfect fit for  SubTropolis,” says Bell. “Companies that do welding or processes that emit fumes would not be a good fit, but it’s a great fit for food, automotive, record storage, or any companies looking for climate control at a lower cost than they would find on the surface.” 

Justin White

The consistent conditions also result in less energy usage. “Tenants don’t have to keep it cold in the summer or warm in the winter,” says Justin White, assistant vice president of operations for Hunt Midwest. To illustrate this point, the SubTropolis team compared the National Archives’ energy costs in SubTropolis to the costs of one of their above-ground locations. The SubTropolis energy use was 91.2% less than that of the similar above-ground facility. 

“We’re always looking for new ways to become more sustainable, such as taking advantage of solar power,” says Bell, who adds that SubTropolis has an ENERGY STAR^® score of 100. “And we have the world’s largest green roof—55 million square feet on the roof provided by Mother Nature.” 

As for utilities, SubTropolis is gas-free and runs entirely on electricity. Tenants have access to water, sewer services, and business-class fiber internet. To maintain air quality, SubTropolis is outfitted with 15 40-foot-wide by 17-foot-tall air portals on the south, east, and north, and utilizes mining-grade ventilation fans to exhaust air at high volume. “The facility naturally breathes, with air entirely cycling through at least every nine hours,” says White. 

Safe and secure

The SubTropolis team prides itself on the underground facility’s safety and security. The property meets and exceeds all four General Services Administration (GSA) security levels for which it qualifies. Security cameras are located throughout the facility, and the portals can be quickly shut and locked in case of a security incident. 

Fire safety is also a priority for SubTropolis. The director of safety serves on the National Fire Protection Association’s committee that develops and maintains fire safety standards in underground spaces. “People don’t realize that about 10% of the industrial market in Kansas City is underground. We want every underground space to be safe,” says Bell. 

Management perspective

Property managers in subterranean developments share many of the same concerns as managers on the ground level, but there are some key differences.

One difference is the underground building codes, which are much different than above-ground codes. Another is the layout of the facility. To illustrate the operational layout of SubTropolis, Bell describes it as a “skyscraper on its side.” “We have a central command center where we can monitor everything, just like in a skyscraper, but laid out horizontally,” says Bell. This layout also makes it much easier for some maintenance tasks, such as air filter changes. “A filter change sounds simple, but filters on a surface building are typically 40-plus feet in the air on the roof. In SubTropolis, it’s a lot easier because they’re at your back door,” says Bell.

The horizontal layout also makes it much easier for tenants to expand or move, and SubTropolis has nearly 6 million square feet of unused space to grow into. “We’ve basically doubled in size since 2011,” says Bell. “If a tenant needs to grow, we can have them in their space in 90–120 days.” Capital expenditure is also significantly less to extend underground than to build on the surface. 

“It’s also imperative to maintain quality and customer satisfaction while you’re growing that much, so it’s harder than just managing a property,” says Bell. “Our team works hard to make sure that service and quality remain unchanged.”

That SubTropolis team includes one director of property management—currently, 2025 IREM Secretary/Treasurer Nominee Ryan Huffman, CPM^®, as well as safety, security, facilities, and project managers. By the end of the year, the team will likely add an assistant property manager.  

Overall, White and Bell say managing subterranean properties has its benefits. “We don’t have to oversee landscaping or roofing, and there are lower costs for managing facility maintenance, HVAC, and pest control needs,” explains White. 

A tight community 

Working underground has formed many bonds for employees— relationships that property managers work to maintain.  

“We try to foster a sense of community spirit, and our efforts have been really effective,” White says. “In addition to bringing people together for regular emergency drills, we offer coffee events, ice cream socials, and company-sponsored educational events like lunch and learns.” 

To ensure everyone’s voices are heard, the team maintains an ongoing email thread for tenants and employees to share security or safety concerns and best practices. 

While potential tenants occasionally question whether their employees will enjoy working underground, Bell says they quickly see the benefits. 

“Employees love that they don’t have to scrape through snow or slush,” he says. “They love that it’s 70 degrees and overcast every day.”