Deep in the Nevada desert is a mysterious block of land called Area 51.
The notorious US air base, believed to be where the military meet and communicate with aliens, is closely guarded at all times.
The site, a detachment of California's Edwards Air Force Base, is tucked away between barren mountains, making it impossible for anyone without top-level security clearance to reach.
But determined alien hunters Tim and Tracey Doyle embarked on the 8,000-foot-high hike to the top of Tikaboo Peak to capture photographs and video footage.
The images are the clearest yet inside Area 51
The pair, who run YouTube channel UFO Seekers, had to use a super long distance lens to capture these never-before-seen images from 25 miles east of the site.
For conspiracy theorists from around the world, the once top-secret location is at the centre of a myriad of claims extra-terrestrials have been landing on Earth for decades.
The notorious air base is restricted to only those with top-level security clearance
In 2013 the Central Intelligence Agency ( CIA ) acknowledged Area 51's exact location in Nevada, near Groom Lake, in response to a Freedom of Information request.
The strip of wasteland in the Mojava Desert, which has been in military hands since before World War Two, had never previously been pinpointed. Before 2013, the very existence of Area 51 was redacted from all requests for information to the media and UFO hunters.
It was President Obama who lifted the lid on this most private part of the United States when he became the first President to acknowledge it by name in a speech.
Area 51 research centre is a Mecca for UFO enthusiasts
In the audience was the actress Shirley MacLaine , who is a long-time believer in alien life.
This was tantalising, but did nothing to explain the wall of silence that existed before.
If the Area 51 files are declassified, it could mark a remarkable breakthrough, considering its actual existence was only officially confirmed three years ago.
So is the truth really out there?
The most persistent Area 51 theory is that a crashed alien spacecraft - along with its extra-terrestrial passengers - recovered from Roswell, New Mexico, in 1947 are stored there.
In an attempt to debunk the story, the US military insists the crash was simply a surveillance balloon that landed on a ranch. This has not been enough to scotch speculation.
Strange craft have been seen flying over the base
Eye-witnesses have regularly claimed to see UFOs twisting and turning in the skies over the base.
They claim scientists working for the military store, examine and recreate alien spacecraft at Area 51.
Alien life forms, living and dead, are also examined here, they say.
No one, however, has ever produced a convincing photo that substantiates the theories.
But speaking in 1989, a man called Bob Lazar claimed that he had worked at Area 51's Sector Four, said to be located underground inside the Papoose Range near Papoose Lake.
Bob Lazar claims to have "back engineered" alien craft at Area 51
Lazar alleged he was contracted to work with alien spacecraft which the US government had in its possession. Bruce Burgess, a 71-year-old mechanical engineer, claimed to be a former employee at Area 51 during the 1950s.
His claims included that he had worked on a "flying disc simulator" which had been based on a disc originating from a crashed extraterrestrial craft and was used to train US pilots.
More outlandish still are suggestions that Area 51 is the undisclosed headquarters for a shadowy one-world government whose existence has never been confirmed.
The alleged codename of this shadowy organisation is Majestic 12, or MJ-12.
According to the conspiracy theories, this was formed in 1947 by President Truman to facilitate the recovery and investigation of alien spacecraft.
This was based on supposedly leaked secret government documents first circulated in 1984.
Upon investigation, however, the FBI declared the documents to be "completely bogus".
It is the stuff of science fiction, the technology that Captain Kirk used in Star Trek.
But for those convinced that Area 51 is the place where America plots the great advances of the future, it must be the venue where time travel could take place.
Captain Kirk with Mr Spock in hit series Star Trek
They cite UFOs as credible evidence of the phenomenon. Beings of the future being contacted and then being persuaded to come back to Earth in the current moment to educate us about what lies in store in the universe.
These theories about Area 51 focus on underground facilities at Groom Lake and even a transcontinental underground railroad system.
People have also claimed there is a disappearing airstrip which briefly appears when water is sprayed onto its camouflaged asphalt.
Area 51 has huge runways and hangars as this satellite image shows
However recent satellite imagery reveals permanently visible landing strips at the lake, which the US Air Force makes no attempt to hide.
Some say that the reason Area 51 is such a tight secret is that it is used to develop highly focused energy weapons, which the US would not want its enemies to discover.
Use of deadly force is authorised against anyone caught trespassing into Area 51
These might be weapons that use radiation, microwaves, lasers and radio waves to disable targets such as cars, drones, jet skis, and electronic devices such as mobile phones.
It would make sense that the military would not want its enemies to know where such experiments happen.
Scientists have already succeeded in quantum teleportation: teleporting information, particles of energy, from one location to another. Area 51 could be the lab where scientists are working on macro-level teleportation, in which human beings can transport their physical bodies into another place.
The Aurora Project
Aurora was a rumoured 1980s American spyplane, the existence of which has never been definitively proved. There is absolutely no substantial evidence that it was ever built or flown. The US government has consistently denied such an aircraft was ever built.
But high-tech propulsion systems have been proposed for a while as an explanation for mysterious unexplained gaps in military budgets and also ear-shattering sonic booms.
In February 1994, Area 51 enthusiast Chuck Clark claimed to have filmed the Aurora taking off from the Groom Lake facility. His footage is not recognised by anyone in a position of authority.
U2 spy plane was test flown at Area 51
But the 2013 official report on Area 51 revealed it was the location of the testing of U-2 spy planes for surveillance during the Cold War as part of the US spy programme.
Details revealed U-2 missions over the Soviet Union and even Britain's participation in the testing project.
Once the U-2 began flying at above 60,000 feet, an unexpected side effect was an increasing number of UFO sighting reports.
Sightings occurred most often during early evenings hours, when airline pilots flying west saw the U-2's silver wings reflect the setting sun, giving the aircraft a "fiery" appearance.
The idea of modifying the weather, to provoke the enemy with a hailstorm or a hurricane sounds ludicrous.
However the perceived threat is serious enough for it to be banned by the United Nations.
Is Area 51 home to a weather control project?
Some suggest Area 51, a place so secret that its existence was denied for decades, would be the ideal place to practice such technology.
Others dismiss such suggestions, trying to modify the weather in the harsh desert would be extremely challenging.
- UFO Seekers is a California based organisation that investigates the UFO phenomenon 365 days a year. UFO Seekers is operated by Tim Doyle and Tracey Sue. They investigate reports of UFOs, aliens, secret projects, and military installations in the United States. They publish a web series on YouTube showcasing their investigations and adventures. For more information, visit www.ufoseekers.com