Two weeks ago (November 18), officers from the Utah Department of Public Safety found a mysterious metal monolith in the middle of the desert while out counting sheep with wildlife officers. The discovery of the structure soon sparked theories about how it got there, as well as a flock of visitors taking road trips to see it in person.

Some theories? Well, Bret Hutchings, a helicopter pilot that first spotted the monolith, reckons it was the work of “some new wave artist or somebody that was a big 2001: A Space Odyssey fan.” David Zwirner Gallery, meanwhile, reckoned it was the previously-undiscovered work of minimalist artist John McCracken, who lived in the nearby state of New Mexico but died in 2011.

Of course, there was also some less credible (but arguably more exciting) speculation that the monolith was a remnant from a secret government science project, or an alien offering.

Unfortunately, before we could get any real answers, the monolith was removed late last week, with photographer Ross Bernards claiming that he witnessed the act. Beside images posted to Instagram, Bernards writes that four men came and toppled the monolith as he was leaving. “They quickly broke it apart and as they were carrying (it) to the wheelbarrow that they had brought one of them looked back at us all and said ‘Leave no trace’.”

The Bureau of Land Management, which was conducting an investigation into the structure, has denied moving it, according to the Associated Press.

There’s no need to take your tin foil hat off just yet though, as another mysterious monolith has cropped up just as suddenly in Romania. Video shared by the local radio station Jurnal FM shows that the object – found near an archeological site overlooking the city of Piatra Neamț – is similar in appearance to the one formerly in Utah, only with a textured metal surface. 

How the Romanian monolith got to be there is no clearer than the one in the Utah desert, either. Andrei Carabelea, mayor of Piatra Neamț, has (albeit jokingly) suggested it’s the work of aliens, while his mention of attracting more tourists has led some to believe that it’s a publicity stunt.

Either way, the mystery deepens even further: an update from Jurnal FM confirms that the Romanian monolith has now also disappeared. “The 2.8 metre (9ft) tall structure disappeared overnight as quietly as it was erected last week,” local journalist Robert Iosub tells Reuters.

However, Iosub also suggests a slightly anticlimactic explanation: “An unidentified person, apparently a bad local welder, made it,” he says, suggesting it might have been nothing more than a copycat prank. “Now all that remains is just a small hole covered by rocky soil,” which could have something to do with the fact that it was installed in a protected archeological area (Piatra Neamț police are investigating).