First it was Utah. Then Romania. And California. Spain. Wales. Paraguay.

The metallic monoliths began to be found in late 2020 by unsuspecting viewers in seemingly random locations around the world.

Often evocative of a science fiction movie prop, the mysterious objects captured the public’s attention and frequently drew crowds hoping to catch a glimpse of the bewildering columns.

Then, earlier this month, another gleaming prism materialized outside of Las Vegas.

“We see a lot of weird things when people go hiking like not being prepared for the weather, not bringing enough water… but check this out!” the Las Vegas Metropolitan Police Department said in a post on X
Police say they don’t know who is responsible for the monolith or how they got it there.

Just what, exactly, are these things? Some have speculated they’ve been deposited on Earth by alien visitors. Others surmise the monoliths might be far-out works of art — or simply playful pranks.

The first monolith appeared in Utah in 2020

In November 2020, the Utah Department of Public Safety announced that a group of workers conducting a count of bighorn sheep noticed a reflective object in a remote section of “red rock country.”

Photos showed the eerie metallic monolith standing before what looked like a rocky Martian landscape.

Utah officials didn’t disclose the location of the object, given that it was extremely remote and lacked resources like restrooms, but onlookers flocked there anyway.

The U.S. Bureau of Land Management said later that month that the monolith had been removed over Thanksgiving weekend by an unknown person or group. Tire tracks and human waste had been left behind, and more than one vehicle had to be towed out.
A monolith that arose in the Romanian city of Piatra Neamt was welcomed by the city’s mayor, Andrei Carabelea, who joked about the object’s puzzling origins in a statement on Facebook.

“My guess is that some naughty, terrifying alien teenagers left home with their parents’ UFO and started planting metal monoliths around the world,” Carabelea said in the statement translated from Romanian.