That’s the great thing about Reddit users: They ask the questions you never knew you were dying to have answered.

The latest example of collective curiosity piquing was generated by user BloodCobalt’s query: “Non-Americans of Reddit, what is your country’s Area 51?”

The US Air Force Base in southern Nevada is part of America’s postwar/Cold War/last 20th century mythology. The top secret facility—its official names are Homey Airport and Groom Lake—has been the source of wild speculation and conspiracy theories. The wreckage from the Roswell UFO crash and other extra-terrestrial artifacts are housed there. It’s been the test range for exotic weapons and aircrafts. The Ark of the Covenant was stored there and worked on by “top men” after Indiana Jones and Marion Ravenwood snatched it from the Third Reich.

Officially, the US government has only confirmed that Area 51 has been used to test highly secret military planes, such as the U-2 spy plane and the F-117 stealth fighter.

But the United States isn’t alone when it comes to clandestine government complexes and military bases. That’s why Reddit users were able to suggest other sites around the world that would be comfortable snuggle buddies with Area 51, cuddling under a mysterious and slightly sinister blanket of secrecy.

Pine Gap, Australia

The sign leading up to the Pine Gap facility in central Australia. (Creative Commons/Wikimedia)

Although located in the center of Australia, this satellite tracking station has more strategic value for the United States than it does for its home country. This site, which has been around since 1970, is a key component in America’s drone program, as well as PRISM, the National Security Agency’s internet surveillance operation. Pine Gap also is central to the ECHELON global intelligence gathering network.

Mayak, Russia Federation

Kysthtym disaster memorial monument (Ecodefense/Heinrich Boell Stiftung Russia/Slapovskaya/Nikulina/Creative Commons/Wikimedia)

There’s very little that’s secret about this enormous nuclear facility in southern Russia. That’s because the power and weapons plant has been the site for some of the most disastrous nuclear accidents in the world. The worst incident, the 1957 Kyshtym disaster, created a fallout cloud that spread more than 300 square miles after a storage tank filled with liquid radioactive waste failed and then exploded. The accident is the third-worst in human history, behind Chernobyl and Fukushima.

“Mayak has seen every single kind of awful radiation accident short of zombies,” wrote Reddit user g3wd, who suggested Mayak. “… Streams and rivers were mysteriously barb-wired. The people really lived a sci-fi nightmare.”

Volkel Air Base, Netherlands

An F-16 fighter hangar at Volkel Air Base in the Netherlands. (Creative Commons/Wikimedia)

Reddit user laughingpinguin was the first to mention this military facility.

As of 2013, Volkel is said to house about 22 US nuclear weapons along with with two F-16 fighter jet squadrons. During the 1962 Cuban Missile Crisis, the airfield stored around 50 nuclear bombs that could be used by the Royal Netherlands Air Force.

Objekat 505, Former Yugoslavia

The mountainside entrance to the underground Željava Air Base complex. (Zlatko/Creative Commons/Wikimedia)

Officially called Željava Air Base (“Objekat 505” was its codename during construction, and it stuck), this underground air base that sits beneath a mountain between the border of Croatia and Bosnia and Herzegovina was one of the largest of its kind in Europe from 1968 until 1992, when it was destroyed by Serbian forces. Because it’s littered with live land mines, the base is used by local law enforcement to train dogs on how to detect the explosives.

Reddit user trlababalan also mentions other theories about the complex’s past uses.

Porton Down, United Kingdom

A 1998 edition of BBC Spotlight discussing germ warfare experiments done by Porton Down scientists. (YouTube)

This government laboratory in southwest England is more the British version of Fort Detrick—America’s former home for biological weapons research—than it is Great Britain’s Area 51. The facility has come under fire because of the secretive nature of the work being conducted there, as well as involvement in human and animal testing. Recently, it gained a new level of global notoriety thanks to a certain Cumberbatchian BBC series, as Reddit user bumblepanda pointed out.

Waihopai Station, New Zealand

Twin radomes protect giant radar dishes at Waihopai Station in New Zealand (Schutz/Creative Commons/Wikimedia)

Like its Australian counterpart in Pine Gap, this global communications monitoring site is part of the ECHELON network and is of vital strategic importance when it comes to electronic intelligence to countries besides New Zealand. The facility also was the site of a visit from an NSA engineer in 2014 who suggested that the station could be used to monitor the Southern Cross cable, the network that contains all of New Zealand’s telecommunications and internet traffic. Privacy advocates and New Zealanders with a conscience were understandably outraged over the idea.

CFB Gagetown, New Brunswick, Canada

This Canadian military base became infamous—as the above video discusses and Reddit user Zanthrous mentions—for being the site where Agent Orange, the carcinogenic defoliant used by the US military in the Vietnam War, was tested in the 1960s.

Vidsel Test Range, Sweden

An aerial drone blasts off at Vidsel Test Range in Sweden

Vidsel is Europe’s largest overland testing facility, and the airspace around this northern Sweden site has been permanently restricted since 1958. Reddit user BloodCobalt provided some details as to why it should make this list: