A third enigmatic monolith has now appeared in California which is similar in appearance to the structures recently uncovered in Romania and Utah.
The first monolith, a four-meter (12ft) high metal block, went viral on social media last week, with a number of Twitter users speculating on its "true" origins before it vanished without a trace.
Commenting on the Utah-based structure, a Utah Bureau of Land Management spokesperson stated:
A number of vloggers filmed themselves visiting the first monolith before it vanished:"Although we can't comment on active investigations, the Bureau of Land Management would like to remind public land visitors that using, occupying, or developing the public lands or their resources without a required authorization is illegal, no matter what planet you are from."
The Bureau later revealed that the monolith had disappeared from the site in a statement posted on Facebook, writing:
"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 second monolith then appeared on BatcaDoamnei Hill in the city of Piatra Neamt, situated in Romania's Neamt County over the weekend. Local police conducted an inquiry into the illegally-installed structure, (believing it to be wholly terrestrial in origin) before it too vanished mysteriously.
Per The Daily Mail, Neamt Culture and Heritage official Rocsana Josanu commented on the strange structure before it disappeared, stating:
"We have started looking into the strange appearance of the monolith. 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."
"Before installing something there, they needed permission from our institution, one that must then be approved by the Ministry of Culture."
The third silver, the rectangular column was found on Pine Mountain in California on December 2 by a group of hikers, who uploaded a picture of it to Twitter soon thereafter.
According to reports in local newspaper Atascadero News, this monolith has not been cemented in the ground like the Utah monolith, which means it could probably be knocked over easily, and weighs an estimated 200 pounds.
There has not yet been any official confirmation as to the purpose or the origin of the structures, and it is unknown if they even stem from the same source. Only time will tell whether or not this one will stay put.