LAS VEGAS (KLAS) — Remember when mysterious monoliths were popping up all over the world in 2020? Well, it happened again, this time in the Nevada desert.

The Las Vegas Police Department shared a photo on Facebook of a monolith that its search and rescue team spotted near Gass Peak, just north of the Las Vegas Valley, over the weekend.

“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 social media post read.

The department had one pressing question about the monolith that remains unanswered: “HOW did it get up there??”

Starting in November 2020, monoliths began appearing around the world, seemingly without anyone noticing who put them there.

The first one was found in an extremely rural part of Utah near Moab on Nov. 18, captivating the world’s attention for days — at least until another one popped up in Romania less than 10 days later. Then, one appeared in California shortly thereafter.

Eventually, the monoliths made their way to Downtown Las Vegas, where one was erected in the middle of the Fremont Street Experience in December 2020.

In total, 23 documented monoliths were found around the world between Nov. 18 and Dec. 8 of that year. A comprehensive list of each monolith was compiled into a Google document.

But just as quickly as the monolith craze appeared, it was gone. That is, until now.

As of Monday evening, no additional information is known about the origin of the monolith that was recently spotted near Gass Peak.

While people try to solve the mystery of the monolith online, the Las Vegas Police Department shared a few tips on how to safely explore the desert — including telling someone about your plans to hike or climb, checking the weather forecast, as well as bringing enough water, food, a first aid kit, a light source, and a fully-charged phone.