Hidden military bases around the world: What secrets do these facilities hold?

Photo Credits: Robert Nickelsberg / Getty Images (cropped).
Photo Credits: Robert Nickelsberg / Getty Images (cropped).

James Bond films are famous for their over-the-top villains and the dramatic, high-tech hideouts they operate from—hidden deep in mountains, buried beneath deserts, or perched on remote islands. But while these secret lairs might seem like pure fiction, real-world militaries have built some equally mysterious and highly classified bases that remain shrouded in secrecy.

From underground bunkers to remote outposts hidden in plain sight, these facilities often spark speculation, conspiracy theories, and curiosity. Some are used for cutting-edge research, while others are believed to support advanced surveillance or strategic operations.

Here are seven of the most top-secret military bases around the world that rival even the wildest Bond villain lairs.

Naval Support Facility Diego Garcia

Aerial view of Naval Support Facility Diego Garcia
Photo Credit: Pictures From History / Universal Images Group / Getty Images

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

Shuttle bus driving away from the entrance tunnel to the Cheyenne Mountain Complex
Photo Credit: Robert Nickelsberg / Getty Images

The Cheyenne Mountain Complex in Colorado is one of the most iconic secretive military facilities in the United States. Built deep inside a solid granite mountain during the Cold War, it served as the main command center for the U.S. Space Command (USSPACECOM) and the North American Aerospace Defense Command (NORAD).

Constructed by the U.S. Army Corps of Engineers, the complex officially opened on February 6, 1967. Its mission was to detect and track threats to North America, including incoming missiles, enemy aircraft, and space-based activity—acting as an early warning hub in the event of a Soviet attack.

In 2008, the majority of its tracking and monitoring operations were transferred to nearby Peterson Space Force Base. However, Cheyenne Mountain remains operational under the 21st Mission Support Group. Today, it serves mainly as a training site and backup command center, standing ready in case primary facilities are ever compromised. Its fortress-like design still makes it one of the most secure military installations in the world.

US Army Garrison Kwajalein Atoll

Aerial view of the secret American military base in the Kwajalein atoll
Photo Credit: Michael Field / AFP / Getty Images

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

Aerial view of Yulin Naval Base
Photo Credit: DigitalGlobe / ScapeWare3d / Getty Images

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

High-security fencing around the perimeter of Porton Down
Photo Credit: Jack Taylor / Getty Images

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

Aerial view of Pine Gap
Photo Credit: DigitalGlobe / ScapeWare3d / Getty Images

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

Lockheed Martin F-35 Lightning II taking off
Photo Credit: Rob Engelaar / ANP /AFP / Getty Images

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.

Rosemary Giles

Rosemary Giles is a history content writer with Hive Media. She received both her bachelor of arts degree in history, and her master of arts degree in history from Western University. Her research focused on military, environmental, and Canadian history with a specific focus on the Second World War. As a student, she worked in a variety of research positions, including as an archivist. She also worked as a teaching assistant in the History Department.

Since completing her degrees, she has decided to take a step back from academia to focus her career on writing and sharing history in a more accessible way. With a passion for historical learning and historical education, her writing interests include social history, and war history, especially researching obscure facts about the Second World War. In her spare time, Rosemary enjoys spending time with her partner, her cats, and her horse, or sitting down to read a good book.

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