After discovering mysterious monoliths in Utah and Romania, a third monolith has been now spotted atop a hill in Atascadero, California, on Wednesday.

The metal slab very similar to a free-standing plank sculpture shared eerie similarities to the monoliths discovered in Utah and Romania.

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Mysteries surrounding monoliths

According to a news report published in the local media outlet Atascadero, the new monolith discovered in California has three sides, but it is not affirmed properly in the ground. However, monoliths discovered in the Utah desert and Romania were fixed firmly in the ground.

The origin of the monolith that appeared in the California mountain remains unknown. Adding up to the mystery, local hiker Ray Johnson told Atascadero that the structure was not there in the mountain on Tuesday.

Alien activities on earth?

It was on November 18 that Utah state officials discovered the monolith in a remote region of the desert. Google Earth Maps suggested that this monolith was placed in the desert between August 2015 and October 2016. However, the monolith mysteriously disappeared on November 27, and on the same day, it reappeared in Romania.

As the origin of these monoliths remains unknown, conspiracy theorists have outlandishly suggested that these events could be activities of an advanced alien species. According to these conspiracy theorists, aliens have been visiting the earth for hundreds of thousands of years, and now, they are gearing up for disclosure. They also believe that the US government and space agencies like NASA are pretty much aware of alien existence on earth. 

Some conspiracy theorists argue that aliens are making use of these monoliths to communicate to their other world. However, there is no scientific evidence to substantiate these claims. But skeptics claim that the installation of these monoliths could be the work of some pranksters, who aim to sow fear in the minds of the general public.