Area 51

Hidden within a ring of mountains deep within the high desert is Area 51, a secretive military installation that exists as part of the Nellis Military Operations Area. It has served as a military test facility since the 1950s, and is well-known for its role in conspiracy theories. 

Originally known as "Site II" or "The Ranch," this mysterious base is where Lockheed tested the first U2 spy planes. They went on to test the SR-71 Blackbird, the A-12 (or OXCART, likely the inspiration for many UFO sightings), and the F-117 Nighthawk at this location. The base is perhaps the most famous clandestine military base in the world. For decades, determined visitors have been attempting to get close, yearning for a chance to unlock its secrets with their telephoto lenses.

Consistently thwarted, the snooping citizens are unable to get close—the area around the base is patrolled by numerous pickup-driving guards armed with M16s, allowed to use deadly force if someone does not halt on entering the base. As of yet, there has never been such an incident, but it's surely a deterrent. Usually, the guards call the local police, who dole out a $600 fine to those curious enough to try and get too close. The closest legal vantage point of the base is at the top of Tikaboo Peak, around 26 miles away. 

For quite some time no reliable (untampered with) aerial images existed of the base, and it didn't show up on any maps. But thanks to its fame and the existence of private satellites, you can now buy high-resolution aerial images of the base from private Russian firms, as well as the firm IKONOS, a private company originally started under Lockheed-Martin.

A new element of the bizarre, famous-yet-secret nature of the base has cropped up as Nevada has begun to realize the tourism potential of Area 51. The state named the adjacent highway "The Extraterrestrial Highway," with nearby towns awash with extraterrestrial key chains, T-shirts, and an alien-themed motel called The Little A'Le'Inn. See what they did there? The minor league baseball team in nearby Las Vegas was even called the 51s (now renamed The Aviators).

While the base is said by conspiracy theorists to be the site of everything from time travel research to an underground transcontinental railroad to a secret lab where aliens work with the government to reverse-engineer alien technology, there is little evidence for any of the fanciful claims that people have made. It's more likely use is just as exciting—a secret testing space for experimental aircraft of a terrestrial nature, many of which could easily be considered unidentified flying objects.

The place became the center of a meme in 2019 when millions declared to storm the location. In the end, only a few hundred people went.