A third metal monolith has appeared in California, continuing a mysterious trend that has captivated conspiracy theories worldwide.

Last month, a mysterious silver monolith appeared and then disappeared in Utah's remote area, garnering widespread attention.

Another similar structure appeared in Romania but also later vanished.

And if two is a coincidence, three is most certainly a trend.

According to reports, yet another metal monolith has appeared on Pine Mountain in Atascadero, California.

The three-sided, three-meter-tall object is similar in shape to those discovered in Utah and Romania.

And as per Atascadero News, this monolith isn't cemented in the ground as firmly as the Utah artwork, however, and someone can knock it over with a push.

The outlet said:

"The three-sided obelisk appeared to be made of stainless steel, 10-feet tall and 18 inches wide."

"[It's] welded together at each corner, with rivets attaching the side panels to a likely steel frame inside."

"Unlike its Utah sibling, the Atascadero obelisk wasn't attached to the ground and could be knocked over with a firm push."

"The Atascadero News estimates it weighs about 200 pounds."

While the object is similar to both the Utah and California monolith, this one appeared in private land. It's also a bit more slender than the Utah version.

California resident Gary Lyons said he came upon the new monolith on Dec 2 during his daily hike on Pine Mountain.

He posted a brief video showing the object, saying:

"I guess this is a thing now, right?"

"Be prepared to see these everywhere."

The objects' origins and real purpose remain unclear. It's also inspiring a mix of fascination, skepticism, and tongue-in-cheek theories.

Social media platforms such as Reddit have even hosted all sorts of speculation about the objects.

Are they art? Are they aliens? Or are they simply pranksters trying to capture the public's attention during a weird, scary, and locked-down year?

The trend dates back to Nov 18, when Utah state officials first discovered a monolith while counting bighorn sheep from a helicopter.

They revealed photos of the object while trying to keep its location a secret. However, netizens tracked it down using public data and satellite footage.

Hikers then flocked to the site, and news of the object quickly spread around the world.

However, no one has claimed it as their own or explained its true purpose.

But on Nov 27, it disappeared with a witness reporting that four men took it away.

He said the men toppled the object, called it 'trash,' and then took it away in pieces. The group also cited the slogan 'leave no trace.'

The second monolith appeared on Nov 26 on Batca Doamnei Hill in Romania.

The Atascadero News said:

"There was no visible evidence of how the object got to the top of the mountain."

It vanished four days later.