By total land area used, the Denver International Airport, DIA for short, is the largest airport in the world, totaling about 52.4 square miles.

As you can imagine, construction took a decent amount of time since the airport uses about 50 square miles.

Construction started around the fall of 1989 and was finally open to the public in February in 1995. This huge airport took almost 6 years to build which sounds about right, but conspiracy theorists think it took too long to build.

Theorists believe there might be an underground city that houses a headquarters for the New World Order, a theory that a group of international elites controls governments, industry, and media organizations, with the goal of establishing global hegemony.

The New World Order supposedly had some sort of role in most of the major wars of the last two centuries; they would carry out secretly staged events, and deliberately manipulated other countries’ economies.

In addition to that, this could explain the amount of contractors that were dismissed during the airport’s construction.

Theorists speculate that dismissing contractors was a tactic to prevent workers from understanding what was actually going on.

This would allow members of the New World Order to build a huge underground facility without anyone questioning it since each contractor would only see a certain amount of the architectural plans and work done.

Now, all of this is just a conspiracy theory. No one knows for sure if there is a underground facility under the DIA, but there are some interesting facts that could support there is.