Sinister sculptures and secret bunkers. Swastika-shaped runways and murals that point to a New World Order takeover or alien invasion.

And what about those gargoyles hanging out by the baggage claim?

Conspiracy theories about Denver International Airport have soared for more than two decades, owing to the airport’s mix of bold public art, unusual architecture, infamous construction problems and an internet-fueled cycle of self-feeding paranoia.

They predate even the airport’s 1995 debut, but Jesse Ventura helped popularize them with a 2012 episode of his TV show “Conspiracy Theory,” and dozens of media outlets from ABC News to the Science Channel continue to report them on an annual basis.

Not that the airport discourages the speculation.

“We have a CEO (Kim Day) who really embraces the conspiracy ideas,” said Heath Montgomery, senior public information officer for DIA. “We decided a few years ago that rather than fight all of this and try and convince everybody there’s nothing really going on, let’s have some fun with it.”

2016 marks a turning point in the airport’s marketing savvy. For the first time, DIA is featuring a modest, museum-style exhibition of the most notable (and, admittedly, least controversial) theories in honor of October as “Conspiracy Month.” Events have included a “conspiracy-themed costume party” and free “Close Encounters of the Third Kind” screening — chosen because the coordinates for the alien landing in the 1977 film supposedly point to DIA’s location (in reality it’s an empty field 51 miles northwest of the airport).

Most of the theories are so laughable and easily disproved that DIA is happy to weaponize them as marketing tools. That, in turn, translates to an estimated “hundreds of thousands or even millions of dollars” in free publicity, Montgomery said.

“Those aren’t even pictures of our airport,” he said as a Buzzfeed video played on a TV screen behind him in the conspiracy exhibit, which runs through Oct. 31 in the main terminal. “People see it out of context and then it continues the dialogue. YouTube is a big propagator of this. There’s been so much misinformation out there that people just regurgitate and spout it without thinking or addressing the reality behind it.”

To get to the heart of their continuing popularity, a Denver Post team was granted behind-the-scenes (and underground) access to examine the theories, facts and history of the country’s sixth-busiest airport, which expects to see a record 58 million travelers by the end of 2016.

Secret societies

The theory: The Freemasons, a centuries-old secret society, has controlled the airport ever since it opened, with ties to the New World Order, a group of global elites who wield power over international affairs.

The history: A dedication plaque at the airport’s south entrance (near the Westin Hotel and RTD University of Colorado A-Line) dated March 19, 1994, contains a time capsule and bears the symbol of the Freemasons, as well as a reference to the New World Airport Commission. “Strange markings” have also been noted around the airport, supposedly indicating secret or alien languages.

The facts: While the Freemasons are a legitimate fraternal (and historically cloistered) organization with civic ties to the airport’s dedication, there is no evidence to suggest they have a hand in ongoing planning or decision-making at the civilian facility. Anti-Masonic conspiracies that date back more than a century were clearly dusted off and updated in advance of 2012’s “apocalypse fever.” The time capsule, to be opened in 2094, contains coins, a signed opening-day ball from Coors Field, Mayor Wellington Webb’s sneakers and a few Black Hawk casino tokens, among other items. The New World Airport Commission was named by Charles Ansbacher — an arts advocate who died in 2010. The name is a reference to Dvorák’s New World Symphony, according to a 2007 Westword article, and the Commission was created only to orchestrate DIA’s opening festivities. The “strange markings” are Navajo-language characters and references to other airport artists.

Artistic clues to the apocalypse

The theory: The airport’s 40-piece public art collection, most notably its colorful, 28-foot-wide murals by artist Leo Tanguma, its “Notre Denver” gargoyle sculptures near the east and west-side baggage claim areas, and the Mustang sculpture (a.k.a. big blue horse, or “Bluecifer”) near Peña Boulevard, are clues to a sinister influence at the airport, alternately credited as Illuminati, Freemasons, New World Order or Nazis.

The history: Like most DIA conspiracy theories, this one roughly parallels the rise of the internet at the time of the airport’s opening and has been given fuel over the years by radio hosts like George Noory, TV conspiracy-backer Ventura and many others. They point to Nazi or fascist imagery in Tanguma’s murals (on Level 5 of the Jeppesen Terminal), the ominous and seemingly random nature of the gargoyles, and the fact that a portion of the 32-foot, 9,000-pound Mustang sculpture (which features glowing red eyes, interpreted as reference to the Four Horsemen of the Apocalypse) fell on and killed its creator Luis Jiménez.

The facts: The meaning of Tanguma’s murals is frequently divorced from the context of their creation, which tells a hopeful story of peace and environmental stewardship following times of war and pollution. Conspiracy theorists focus only on the grim imagery but not the rainbow-laden resolution (read from right-to-left in the mural “Children of the World Dream of Peace”). The red eyes in the Mustang sculpture are an homage to the artist’s father, who worked with neon signs. “Hindsight’s 20/20, because it really could have been any color of neon,” said Heather Kaufman, director of arts and public events for DIA. And the gargoyles? They have historically been used as decorative yet functional downspouts, and in general, as longtime symbols of protection to ward off evil spirits. In DIA’s case, they’re playfully popping out of open suitcases on pillars.

Underground bunkers — and aliens

The theory: Hidden beneath the airport’s underground baggage-transport tunnels is a secret bunker (or series of bunkers) designed to house billionaires and global political elite in the event of an apocalypse. Lizard people (a.k.a. “Reptoids”) and/or evidence of aliens are also thought to be lurking down there.

The history: Contractors who originally worked on the airport, which went over budget and opened 16 months behind schedule, reportedly saw evidence of bunker entrances and unexplained tunnels. A multi-million dollar automated baggage system failed to work as designed, fueling doubts about the intent and scale of the construction. An “alien” drawing has appeared on the walls, and blurry footage of “lizard people” has appeared on conspiracy websites.

The facts: Roughly 1,000 people work daily in the various levels underneath the airport, ferrying luggage among ticket counters, planes and baggage claim areas in a pair of 7,000-foot long tunnels that run alongside the airport’s underground trains — which were not immediately ready to use upon the airport’s opening. As seen during a tour of the tunnels provided to The Denver Post, all plumbing and electrical infrastructure appears to end at the underground area’s lowest level; hiding anything else under it would be an engineering feat on par with the “Chunnel” that connects England to France. Furthermore, “Over the years, little personal touches have been made,” Montgomery said of the tunnels, pointing to the hand-drawn alien image (as well as decidedly non-alien-themed “graffiti” like smiley faces) as he drove an electric golf cart under the B concourse. The automated baggage system was actually used in various capacities, mostly by United Airlines, up until 2010. “There’s a certain mystique to anything you can’t see,” Montgomery said of the 470,000 square feet of underground space. “The fact of the matter is, it would take me three days to show you everything down here.” Finally, airport workers have been known to don lizard masks as pranks while the media are on tours — including one caught on camera by Fox 31 KDVR-Denver in a video that has since been circulated (often uncredited) as evidence of their existence.

Nazi runways, remote locations

The theory: DIA’s location, approximately 25 miles from downtown Denver, swastika-shaped runway configuration and various, barely concealed symbols of Nazism or fascism hint at any number of sinister plots, theorists say. Also, a tunnel is said to connect DIA to NORAD, nearly 100 miles to the south near Colorado Springs.

The history: Nazi conspiracy theories have been among the most popular online for the last two decades, and despite its recent, tongue-in-cheek embrace of most conspiracies, DIA officials have shied from directly addressing them — which some see as a sign of their validity. “We do have some subject matter that we wanted to either just avoid or tread very lightly with,” said DIA’s Kaufman, in response to a question about what made the cut for October’s exhibit in the main terminal. “Some things are worth debunking. Others aren’t.”

The facts: A close look at aerial photography of the supposedly swastika-shaped runaways reveals a lumpy, misshapen and largely interpretive swastika, at best. The rotating, fan-shaped design allows for optimal take-off into and against the wind from different directions, depending on weather and traffic patterns. Additionally, a 90-mile long tunnel from DIA’s remote location to NORAD seems highly unlikely and cost-prohibitive, given that the world’s longest underground rail tunnel — the newly opened, Swiss Alps-traversing Gotthard Base Tunnel — is less than half that length (35.4 miles) and took more than a decade to excavate and construct.

Conclusion

For people with vested interests in sowing doubt about institutions and organizations, the real fear might just be discovering there’s a mundane explanation for all these theories. Conspiracies create drama and excitement, allowing theorists to more clearly define (and usually reinforce) their existing beliefs. They feel alive, adrenalized and righteous.

But a more complex, gray-area explanation of things may be the biggest unacknowledged threat to those with a stake in defining themselves against systems they don’t (or don’t want to) fully understand.

Theorists, for example, have never successfully addressed this notion: If the airport and its backers have spent decades and billions of dollars hiding secret, global plots and infrastructure, why jeopardize that work by putting so many obvious clues in plain sight?

“No matter what you do, you lose,” Mongtomery said. “You show people the tunnels and explain the symbols, you lose. You clam up and deny it, you lose. So that’s why we’ve started to have fun with these, because people are going to believe what they believe, regardless of hard evidence.”