Beneath Kansas City's streets lies an unexpected wonder—SubTropolis, the world's largest underground business complex, spanning over 6 million square feet in a 270-million-year-old limestone deposit.

Carved out of limestone in the 1940s, this hidden metropolis was the vision of Lamar Hunt, famed founder of the Kansas City Chiefs. Originally a mining site, SubTropolis has become an essential part of Kansas City’s economic landscape.

The origins of SubTropolis date back to the late 19th and early 20th centuries, when extensive limestone mining operations supported Kansas City's rapid expansion. When demand for limestone dwindled, the vast network of tunnels left behind presented a unique opportunity.

Recognizing the potential of these naturally climate-controlled spaces, Hunt transformed the old mines into a modern underground city, officially opening SubTropolis in the 1960s.

SubTropolis quickly attracted a range of tenants, including major companies like Ford Motors, Pillsbury, and Russell Stover. Ford, for instance, uses the underground space to store vehicles and customize truck beds in a controlled environment. In the early 1970s, Ford leased 25 acres of underground space to store thousands of unsold vehicles until they could be sold.

The stable temperature of 65 to 70 degrees Fahrenheit makes it ideal for preserving delicate items, such as original film reels of Hollywood classics like "Gone with the Wind" and "The Wizard of Oz," stored deep within SubTropolis. The US Postal Service and the National Archives also lease space in the naturally climate controlled space.

*Courtesy* *YouTube* */ Great Big Story.*

Covering an area large enough to fit 42 Arrowhead Stadiums, SubTropolis is a marvel of modern engineering. Over 10 miles of paved roads crisscross its tunnels, well-lit by energy-efficient LED lights.

The limestone walls act as natural insulators, significantly reducing the need for heating and cooling, earning SubTropolis a perfect 100 percent rating from ENERGY STAR®.

Safety and security are paramount in SubTropolis. The limestone pillars supporting the tunnels are six times stronger than concrete, making the complex one of the safest places to be during natural disasters. Security measures include 24/7 surveillance and commissioned officers, essential for the government agencies and high-value tenants housed within the complex.

As SubTropolis continues to evolve, plans for expansion are already underway, with another 8 million square feet of industrial space set to be developed.

What began as an abandoned limestone mine has become a thriving underground city, a testament to Lamar Hunt's ingenuity and resilience.