James Bond movies are well-known for their extravagant villains and the elaborate, high-tech headquarters they control—tucked inside mountains, buried under deserts, or isolated on distant islands. Although these cinematic hideouts may seem far-fetched, real-world militaries have constructed equally enigmatic and tightly guarded facilities that remain cloaked in mystery.
These secretive sites range from deep underground bunkers to unassuming outposts hidden in plain view. Their true purposes often fuel rumors, stir up conspiracy theories, and attract worldwide fascination. Some are centers for advanced military research, while others are suspected to house powerful surveillance technology or support covert missions.
Here’s a look at seven of the most secretive military bases on Earth—locations that could easily rival any villain’s lair from the Bond universe.
Naval Support Facility Diego Garcia
Naval Support Facility Diego Garcia is a secret joint British-American military base located in the Indian Ocean. The site was constructed in 1971 after the native population (the Chagossians) was forcibly removed. It was initially home to 20 deepwater logistics ships, but, eventually, a naval air field was opened and operated between 1981-87.
Although Naval Support Facility Diego Garcia is in a strange location, 1,000 miles from India, it’s proved vital on many occasions. When the Iraq War began, it provided logistical support. Until the Americans could establish their own bases on enemy soil, they were reliant on the island as somewhere for aircraft to land and takeoff.
In more recent years, the area has become an important location for tracking satellites and objects in deep space using Ground-Based Electro-Optical Deep Space Surveillance.
Cheyenne Mountain Complex
Tucked deep within a granite mountain in Colorado, the Cheyenne Mountain Complex stands as one of America’s most well-known secret military installations. Originally built during the Cold War, the facility was designed to house the primary command center for both NORAD (North American Aerospace Defense Command) and U.S. Space Command.
Engineered by the U.S. Army Corps of Engineers, the complex officially began operations on February 6, 1967. Its core function was to act as an early-warning station, tracking potential threats to the North American continent—including ballistic missiles, hostile aircraft, and activities in space—should the Soviet Union launch an attack.
By 2008, most of its monitoring responsibilities had shifted to Peterson Space Force Base nearby. Still, Cheyenne Mountain remains active, now operating under the 21st Mission Support Group. It primarily serves as a backup command center and training location, ready to take over if other facilities are compromised. With its hardened, bunker-like construction, it remains one of the most secure military sites anywhere on the planet.
US Army Garrison Kwajalein Atoll
During the Second World War, the US performed an amphibious landing on the island of Kwajalein and never left. There were Japanese troops stationed there who were either captured or killed. A secret military base was established there as the conflict drew to a close, acting as a staging area for Operation Downfall – the planned invasion of the Japanese homeland.
Instead of giving up the island when the war ended, the Americans stayed and established it as one of their command centers for nuclear testing in the Marshall islands. As a result, much of the local population was pushed out, and those who remained worked in labor camps.
With the end of the Cold War, much of the nuclear testing was canceled and the size of the US Army Garrison drastically shrank. That isn’t to say that they left completely, as there’s still a military presence on the island. In fact, the Americans have it leased until 2066.
At present, Kwajalein atoll is home to the Space Fence radar, which is used to track space debris and satellites. It’s also one of five ground stations used to control GPS technology.
Yulin Naval Base
The Yulin Naval Base, operated by the People’s Liberation Army Navy, is one of the most mysterious military facilities in the world. Located along the coast of Hainan Island in the South China Sea, details about this highly secretive base are scarce. Most of what is known comes from open-source intelligence and satellite imagery, which suggest that construction began sometime around 2000. Even as recently as 2022, the base is believed to still be unfinished, with two additional docks under construction.
The facility features both above-ground and underground submarine docks. Satellite images have captured weapons being loaded onto submarines, but the exact types and quantities remain unknown. While the base also accommodates warships, its primary purpose is to house nuclear submarines, which access the site through a semi-submerged tunnel carved into the mountainside.
Porton Down
Porton Down, still in operation today, is the world’s oldest chemical warfare research facility. It’s also incredibly controversial. Located in Wiltshire, England, Porton Down began as the War Department Experimental Station in 1916 and opened in response to the German use of chemical weapons in World War I. Those employed there were tasked with researching possible solutions, as well as improving respirators.
Although it remained open during the interwar period, this secret military base was, again, fully staffed during the Second World War, when the research focused on studying newly-discovered German nerve agents and creating British biological weapons. The main criticism of the establishment was that the tests all took place on human subjects – so-called “volunteers” – who were conned into participating. Many died or suffered long-term health consequences from the tests.
Still in operation, Porton Down holds samples of many deadly pathogens, including anthrax, the Black Plague and Ebola. Those who work there are still active in analyzing mysterious chemicals, viruses and pathogens.
Pine Gap
This secret military base, located in the Australia Outback, is certainly a sight to behold, with its large white spheres. It’s jointly operated by Australian and American forces – including the Central Intelligence Agency (CIA), National Security Agency (NSA) and the National Reconnaissance Office.
Despite its remote location, Pine Gap plays an extremely important role in international reconnaissance and intelligence. It’s the control center for many spy satellites, which travel over Russia, the Middle East and China. In fact, the site was chosen specifically because it’s too far away for these signals to be intercepted by spy ships.
Pine Gap was opened in 1970 and initially designed to focus on detecting nuclear threats and Soviet missiles during the Cold War. It has now moved toward supporting the US military by detecting airstrikes, as well as intelligence and data gathering.
Volkel Air Base
There are only three places in the world that don’t show up on Google Maps, including the last entry on our list of secret military bases: Volkel Air Base. It’s not exactly clear why it can’t be found, especially as it’s easily located by those living in the area. The most popular theory is that it has stored weapons for the US Air Force since the Cold War. This hasn’t been commented on by the Dutch Minister of Defence, but leaked documents indicate there are these types of weapons in the Netherlands.
Volkel Air Base was actually created by the occupying Germans in 1940, first for use as a diversionary base for Allied bombings, and, later, as a fully-operational Luftwaffe base. Following Allied attacks on the airfield as part of Operation Market Garden, the Germans were no longer able to use it. The Royal Air Force (RAF) briefly did, however, after they gained control of the area.
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In 1949, the base was used by the Dutch Naval Aviation Service (MLD) for training, before being restored to a functional airfield by the Royal Netherlands Air Force (FNLAF) a year later. It’s still in use today, and may or may not have nuclear weapons.