When archaeologists go digging through old buildings, there are a few things they're expecting to find. They will probably find some bones, maybe some interesting pottery, or some old weaponry, but sometimes they discover something that even surprises them.

However this time, archaeologists found something that led them down a crazy conspiracy theory, in an investigation about a cult that has been confusing people for decades now.

They discovered a pair of coins hidden under the seats of Bath Abbey in the United Kingdom, but on those coins was a devil and the words "Civitas Diaboli" which translates to "The City of Devils."

The coins also feature a reference to a discovery on an island. It says "13 MAJ (May) ANHOLT 1973," which refers to an incident that took place on the island of Anholt.

The archaeology firm explained what was found on that site in Anholt. "Thirteen "˜ritual sites' were discovered by local residents which precipitated an investigation by police from the Danish mainland."

It included masks, bones wrapped in string, candles, and a shrunken head on a stick. The shrunken head turned out to be a fake, but still creepy.

Over the years, these weird discoveries continued. They found mysterious devil coins all over, and as they did, more and more details of the "Anholt cult" started to pop up. Whether it was letter from a satanic high priestess or paintings hidden being police stations, the date was always listed as May 13th, 1973.

They've managed to find 400 coins over the years, and thought they may be able to use them to discover the truth about this mysterious "Anholt cult," but recently it was discovered that this whole thing has been an elaborate prank, set up years in advance.

The worst part is that the man who has been working on it wasn't even alive for the big reveal!

Knug Langkow lived in Denmark, and for decades his plan to fool the world worked. So many people believed that there was this mysterious cult that was murdering people on the island of Anholt, but in 2013 a Danish newspaper did a full investigation and uncovered the truth.

While Langkow had already passed away by the time the newspaper looked into it, his niece, Lene Langkow Saaek, was ready to explain his reasoning.

"I think normality annoyed him. He did not like ordinary."

He had a strange sense of humor, one that was shared with a coin expert named Jí¸rgen Sí¸mod, and a coin engraver named Bent Jensen, so together they came up with the design and minted hundreds of the coins.

Bruce Eaton was the journalist who investigated it, and he thinks that the best part about this prank is how big it's gotten.

"The full scale of what he was up to has never fully been understood.

"The truth is even more interesting "“ this guy is creating false narratives, an alternate universe where this cult exists.

"He's trying to create a mythology about this island of Anholt. It's odd but he seems to have enjoyed it."

The fact that he was able to create this fake cult, and put so much detail into it is probably what's most impressive. Eaton explains that it's the physical objects that confused the archaeologists the most.

"As archaeologists we put a great deal of store by physical artefacts.

"Written records of the past can be biased or falsified but you can say "˜here's a physical object' - it shouldn't lie, its a real connection to the past.

"But in this case these physical objects are a total fabrication. That fascinates me."

According to his daughter, Langkow "did it to make fun of the bourgeoisie and to get people out of their chairs and to wonder."

Apparently there are more pranks that haven't been confirmed yet. Eaton found evidence that Langkow brought a bunch of plants from the south of Denmark up north in hopes that it would "mess with botanists."

It hasn't been confirmed yet, but if you ever hear of anything crazy happening in Denmark, there's a good chance that it's Knug Langkow.

While this cult turned out to be fake, there have been some very scary cults over the years.

Some of your favorite actors actually grew up in cults, like River and Joaquin Phoenix.

And there have been other situations where people in churches have been 'possessed by Satan.'

Source - Bristol Live / Fox News