Last week, officials in Utah revealed they had found a shimmering, metal structure deep in the Red Rock desert, but refused to say exactly where or what it was.

However, the mysterious monolith suddenly vanished, and nobody knew how or why...

And now, just to make matters even weirder...

A strange and cryptic message has been found at its original location.

Now, it all started last Monday during a routine wildlife check...

But it quickly took an extraterrestrial turn.

Officers spotted a mysterious monolith right in the middle of rural Utah.

The Utah Department of Public Safety took a helicopter over the desert when the strange sighting took place earlier this week.

They were helping the Division of Wildlife Resources do a routine count bighorn sheep...

When they suddenly noticed a strange-looking object on the ground.

The object appeared to come straight out of 2001: A Space Odyssey.

"One of the biologists spotted it, and we just happened to fly directly over the top of it," pilot Bret Hutchings said.

"He was like, 'Whoa, whoa, whoa, turn around, turn around!' And I was like, 'What.' And he's like, 'There's this thing back there, we've got to go look at it!'"

And there it was.

Right in the middle of a clearing in the rock stood the strange object.

Hutchings said it was easily "between ten and twelve feet high."

Although he admitted it didn't look like it had fallen to the ground...

But instead, placed there on purpose.

"We were kind of joking around that if one of us suddenly disappears, then the rest of us make a run for it."

Still, Hutchings thought the object was more than likely placed there by a human, rather than an extraterrestrial.

"I'm assuming it's some new wave artist or something or, you know, somebody that was a big 2001: A Space Odyssey fan," he said...

In reference to the 1968 film where a large black monolith appears to study early civilization.

Although it was all pretty exciting, the DPS quickly confirmed that it is illegal for any forms of artwork to be placed without permission...

"No matter what planet you're from," they said in a statement released Monday.

Well, this didn't stop people from visiting the eerie monument.

Tourists were quick to track down the monolith to investigate themselves and, of course, some wild theories were born as a result.

Speculation was rife as to what the monolith could be...

Or where it even came from in the first place. Let's take a look at some of the best theories born on the internet...

Firstly, it could be an art structure.

One of the more popular theories - and one supported by officials themselves - is that the monolith could have been made and placed by an artist.

Which artist though?

A gallery owner recently claimed the work may be a tribute to the art of the late artist John McCracken, who created similar-looking objects before he died in 2011.

A second theory was that it could be alien evolutionary device.

Thanks to its resemblance to the famous object from Stanley Kubrick's 2001: A Space Odyssey, many can't help but jump to a science-fiction conclusion.

Thirdly, it could be an alien probe.

Besides having some specific impact on the inhabitants of planet Earth, the monolith could "just" be an extraterrestrial probe, sent here to learn about our ways. But would placing it in the middle of the Utah desert be the best place to probe humanity?

However, others believe that it could be a Kubrick fan installation.

The visionary director left a profound legacy, garnering millions of fans around the world. As the monolith he devised for 2001: A Space Odyssey is one of the most famous objects in movie history, it's not out of the question that one of the director's followers decided to recreate it.

And, lastly, some believed that it could be a government "control device."

Because of course, they did. The American Southwest is rife with government military installations and mysterious bases like Area 51. Having the monolith be a part of some government experiment is a connection that's easy to make for any conspiracy-minded Internet dweller.

Of course, the actual government hasn't confirmed any of this.

But the DPS has warned people against trying to find it: "It is in a very remote area and if individuals were to attempt to visit the area, there is a significant possibility they may become stranded and require rescue."

And then, just to make this story even more mysterious...

The monolith suddenly vanished!

According to the New York Times, the monolith disappeared into thin air.

The Times reported over the weekend that the monolith had been removed - however, Utah authorities say they had no idea who removed it.

Utah's Bureau of Land Management confirmed the news.

In a statement, they revealed that the structure was removed on Friday evening by "an unknown party."

"IT'S GONE!"

Posting to Facebook, the Bureau of Land Management wrote: "We have received credible reports that the illegally installed structure, referred to as the “monolith" has been removed from Bureau of Land Management (BLM) public lands by an unknown party. The BLM did not remove the structure which is considered private property. We do not investigate crimes involving private property which are handled by the local sheriff’s office."

One word. Aliens.

The post continued: "The structure has received international and national attention and we received reports that a person or group removed it on the evening of Nov. 27." It was definitely aliens, wasn't it? Maybe...

And then, to make things even weirder...

The monolith suddenly showed up at the Petrodava Dacian Fortress in Romania. "We have started looking into the strange appearance of the monolith," said Neamt Culture and Heritage official Rocsana Josanu.

"It is on private property, but we still don't know who the monolith's owner is yet. It is in a protected area on an archaeological site."

What does it all mean?

And now, just when you thought there couldn't be more twists in the tale, a message has been discovered at the monolith's original location.

In a lengthy Instagram post, monolith-hunter, Riccardo Marino, wrote: "All that was left in its place was a message written in the dirt that said 'bye b***h' with a fresh pee stain right next to it."

"Someone had just stolen the statue, and we were the first to arrive at the scene."

"We arrived at the location to see nothing but the foul markings left and we realized we must have been the first people to see it removed."

Watch the full video right here.

And for more aliens, scroll on ...