An eagle-eyed UFO enthusiast spotted three “secret mountain entrances” to Area 51 – the US Air Force base in the Nevada Test and Training Range – using Google Maps.
Scott C. Waring, a YouTuber who runs a channel focused on extraterrestrial life, claims he discovered a previously unknown underground base near Area 51.
Area 51 is shrouded in mystery and is known as the US home of “UFOs,” which believers think houses evidence of alien life.
Mr Waring said he used Google Earth to examine the facility when he noticed three bizarre entrances on the edge of a mountain near the site.
He claims one is “large” and estimated to be 18 metres by 9 metres in height, and there are also two “small” ones.
Waring claims there are air ventilation pipes coming out of the largest “entrance” and two installed on top of the mountain.
In addition, the ufologist spotted what he thinks are “two guard towers” near the entrance of the underground base.
The base is said to be located between between Area 51 and Nellis Air Force Base, and close to an area where, in 2006, Waring claimed he spotted a 30-metre UFO with electric pipes coming out of it.
He said the UFO was parked on a runway, but failed to provide any evidence of the bizarre moment, casting doubt on his claims.
Area 51 was built in the middle of the 20th century, but US authorities officially acknowledged its existence only in 2013.
People claim the site is where the government keeps UFOs and aliens, a suggestion US officials have repeatedly denied.
Despite this, witnesses have claimed to have seen alien spacecraft above or near the area.
Last year, more than two million people responded to a Facebook event inviting them to storm Area 51.
The military discouraged people from attempting to enter the military property and warned against trespassing.