Massive network of tunnels beneath US airport to finally be revealed after years of conspiracy theories

The underground labyrinth has fuelled conspiracy theories involving secret bunkers, "lizard people", underground military facilities and more for years.

But they will now be opened up to the public as a walkable alternative to Denver Airport's current train system.

In a statement, Denver Mayor Mike Johnston said: "We've heard loud and clear that easier, more reliable ways to move between concourses has been a top priority.

"And who knows, maybe along the way, travellers will finally get a closer look at the underground tunnels and decide for themselves what's fact and what's fiction."

Construction on the project is expected to begin in 2027.

The project will not be funded by the taxpayer and instead use airport revenue, Denver International Airport CEO Phil Washington told CBS News.

It is expected to cost between $300miillion and $700million, and will coincide with the airport's "Vision 100" expansion plan, which will renovate its Great Hall.

The airport has previously leaned into the conspiracy theories which have surrounded it since its 1995 opening was delayed by more than a year.

In 2018, the airport launched its "DENFILES" campaign, which featured images of lizard people, UFOs, secret tunnels, and green aliens on construction hoardings.

One advertisement read: "What are we doing?" before listing three options, "adding amazing new restaurants and bars", "building an Illuminati headquarters", and "remodeling the lizard people's lair".

Denver International Airport is also known for its 32 feet tall statue of a mustang - officially titled "Blue Mustang" but more commonly known as "Blucifer" - which killed its sculptor Luis Jimenez when a piece of it fell on him at his studio.

The statue, also notable for its red glowing eyes, appeared on a DENFILES advertisement shooting lasers from its eyes and a caption which said: "Are we creating the world's greatest airport? Or preparing for the end of the world?"

One conspiracy theory surrounding the airport and its tunnels is the belief there is an underground city within Denver Airport used to host members of secret societies.

They have also been theorised to hose extraterrestrials, lizard people, or after the horror movie "Us", a community of doppelgangers.

But the airport has insisted the tunnels are less than two miles long, and are host to work and office spaces rather than secret buildings and bunkers.

The airport has also previously hosted an art exhibition named "Conspiracy Theories Uncovered" which showcased photography and artwork related to the conspiracy theories.

This included an "alien skull" alongside photography of the tunnels and artwork within the airport.

Artwork within the airport which has fuelled conspiracy theories include two "luggage gargoyles" in the baggage claim area, and a mural titled "Children of the World Dream of Peace" which features imagery some believe foretells an apocalyptic future controlled by elites.