That's Cool!

-- It has nearly 5 million square feet of leaseable space; which can be expanded to up to 20 million.
-- It has more than 50 tenants occupying 120 buildings on some 120 acres (its largest tenant is the U.S. Postal Service).
-- It includes over 6 1/2 miles of paved roads, and over 2 miles of railroad track.
-- It includes nearly 400 truck dock locations.
-- It's just 20 minutes away from Kansas City International Airport, with easy Interstate access.
-- More than 1,300 employees work here.

But did I add that:

-- It maintains consistent year round temperatures, without need for heating or air-conditioning.

Have a guess?

What if I added that it includes more than 10,000 limestone pillars.

Subtropolis, located in North Kansas City, is one cool industrial park. Indeed, it's the largest underground business complex in the world.

Subtropolis was created in the space left from mining 270-million year old limestone deposits, removed by the "room and pillar" method, leaving 25-foot square pillars that are spaced 40 feet apart.

Assistant General Manager Dick Ringer gave me a tour of some of this vast subsurface space on a hot Kansas City afternoon. While temperatures were in the lower '90s outside, we drove through the complex without breaking a sweat. Dick told me that in essence Subtropolis -- which is owned by Hunt Midwest (the Lamar Hunt family business) -- operates just like any other industrial park.

But there are a few key differences. One is the fact that occupancy costs are considerably lower, given that there's no need for heating or cooling. The other is that it is just a bit strange to drive through a portal into an underground space (it's all on the same level as where you enter), and then find yourself on an internal roadway network.

You pass well-lit signs identifying business entrances, and even stop signs in front of railroad track crossings (there's not much current rail service -- though the capacity is there and has been used by some tenants).

The largest single tenant right now is the U.S. Postal Service, which finds Subtropolis ideal for storing huge quantities of stamps. But you'll also find a number of paper companies (such as Hallmarks); a children's learning center; and even a new "building" that can store between 200 and 300 boats and RVs.

See the photo below; and click here to run a 360 degree panorama of the interior (note, since it's June, most of the boats are out on lakes and rivers, so the building is fairly empty right now).

"Buildings" within the complex are roughly 80,000 square feet in size, and have ceilings a uniform 16 feet high. The interiors are customized by the individual tenant.

John Keeney, who manages the underground boat and vehicle storage facility in Subtropolis, told me that some employers have told him that one benefit is that there's no cellphone reception underground -- this seems to boost employee productivity! Land lines are available. He also noted that there's excellent natural ventilation through the portals on the north and south sides.

The land above Subtropolis is also in use for industrial purposes -- so you're dealing with a highly efficient use of vertical space.

With Subtropolis and several other underground storage facilities, some ten percent of all industrial space in the Kansas City area is underground. And did I mention that the annual Ground Hog Run draws over 3,000 participants to a 5 or 10 kilometer run.