Strange circular patterns in the Mexican desert are believed to be spaceship landing marks to help guide Scientologists back from outer space.
Aerial pictures taken from a helicopter also show a house-like structure that covers the entrance to a vault.
This alien space cathedral contains a vault with the works of Scientology's founder, the science fiction writer L Ron Hubbard, who claimed that humans are extraterrestrial beings.
Hubbard's writings are preserved for eternity on stainless steel tablets, on gold discs and encased in titanium capsules.
The only-non Scientologist to have visited this site is Tim Gallagos, an ex-police chief of the Las Vegas, New Mexico, Sheriff's Department. He was given a tour of the vault by church officials in the late 1990s.
He told MailOnline that within the stone walls are several machines for copying the works of cult leader Hubbard.
Galagos explained: "They were transferring writings, speeches and videos. This vault is like a giant time capsule and they told me all the scriptures are being kept there."
Ex-Scientologists have also told BBC journalist John Sweeney that the "alien space cathedral" was built deep underground by the church in the 1980s, and cost millions of dollars.
In his book The Church of Fear - Inside the Weird World of Scientology, he reports how he was told the vault "houses the lectures of church founder L Ron Hubbard on gold discs locked in titanium caskets sealed with argon. The cathedral is H-bomb proof, protected by three 5,000lb stainless steel airlocks."
He adds: "Experts say the weird signs on top of the mountain will guide Clears, [high-ranking Scientologists] returning from space to find Hubbard's works after a nuclear Armageddon wipes out humanity."
A spokesperson for the Church of Scientology responded to the allegations: "Church of Spiritual Technology (CST) cares for the long term preservation of L. Ron Hubbard's writings and lectures. It uses cutting edge long-term archival preservation methods to ensure that Mr. Hubbard's written and recorded works will be preserved for future generations.
"The facility in New Mexico is an archival storage site containing preservation copies of Mr. Hubbard's writings and lectures. The symbol carved in the hillside near the facility is CST's corporate logo. Because the facility is in such a remote area the only way to it is by way of a nearby airstrip.
"The corporate logo is carved into the ground to help pilots find the airstrip, as there is no control tower or air traffic control. Also, using land to display the logo of a corporation's headquarters is not uncommon as detailed graphically in the publication Off the Map, by Alex Turnbull and James Turnbull, which includes many illustrations of corporate logos visible on Google Earth."
The Church of Scientology was founded in 1953 by Hubbard, who wrote that 75 million years ago, an alien ruler called Xenu brought billions of his people to Earth in a spaceship and then killed them in a bomb blast, leaving their spirits to wander around and harm the living.
According to the Church of Scientology, the 50-year-old religion now has more than eight million members in 159 countries.
The church's most famous celebrities include John Travolta, Tom Cruise and Nancy Cartwright, who is the voice of Bart Simpson.