6 THUMS Islands, California 

In the 1960s, a set of artificial islands called the “THUMS Islands” were created near Long Beach, California, complete with man-made waterfalls, buildings, and other structures. Despite seeming like resort islands, they are actually used to camouflage the oil drilling activities of four companies. These islands are also specifically designed to make the drilling activities soundproof. 

Built-in the 1960s, the THUMS Islands are a set of man-made islands named after five oil companies – Texaco, Humble, Union, Mobil, and Shell. These islands are located off the coast of Long Beach, California, and are ringed with palm trees, blue and white towers, waterfalls, and more. Yet, despite their “resort island” appearance, these structures are not open to visitors.

This is because the THUMS Islands are actually four private islands built to disguise the oil drilling activities of their owners. The structures on the islands were designed by Joseph Linesch, the architect of Disneyland, who succeeded in not just hiding the oil wells but also making them soundproof.

Therefore, even today, these islands continue to amaze observers. In 1967, the islands were renamed the “Astronaut Islands” to honor the American astronauts killed while preparing for the Apollo 1 mission. (1, 2)

7 Building 470, Maryland 

Building 470 was a seven-story building constructed in Fort Detrick, Maryland during the 1950s. Although it appears ordinary, it was designed to be used as a bioweapons lab that ran tests on anthrax specimens. To pass the structure off as an office building or barracks, fake windows and window sills were also added to its exterior.

During the Cold War era, the U.S. Army built a curious structure within its base at Fort Detrick, Maryland. This structure was a seven-story building called “Building 470” that looked rather unremarkable on the outside. However, on the inside, it housed a bioweapons lab that produced anthrax specimens. It had simply been disguised to look ordinary with the help of fake windows and window sills. 

Not long after, in 1969, the building was abandoned when President Richard Nixon shut down the bioweapons program. Afterward, the structure was decontaminated and turned over to the National Cancer Institute (NIC) who used as a storage facility.

In the 1990s, experts determined that the building was too dilapidated for safe use and recommended that it be demolished. Finally, in 2003, after another extensive environmental test, the building was knocked down by the National Institutes of Health (NIH). (1, 2)

8 Gravesend Training Facility, England

Since 2003, the English town of Gravesend, Kent has been home to extremely violent activities. At first glance, this entire structure even resembles an urban setting, complete with shops, parks, clubs, and more. However, the only occupants of this place are London police officers who are being given public order and firearms training at this facility.

Since 2003, the English town of Gravesend, Kent has been home to a neighborhood that is constantly rife with riots and shootouts. This neighborhood looks like any other, with its high street bank, post office, restaurant, pub, sports stadium, and more. But despite the near-constant violence, there are no residents in this town. 

In reality, this neighborhood is a part of the Metropolitan Police Specialist Training Center, a facility built to train police officers in public order and firearms usage. The town successfully mimics an English community, allowing police officers to practice disarming rioters with various tactics. 

Built by Cubic Range Design Solutions, a private defense contractor, this facility also boasts of an indoor, 3D simulation unit that specializes in firearms training. It also contains stables for ten horses so that mounted police units can be trained to disperse crowds or oversee peaceful protests. (1, 2)

9 The James Henry Greathead statue, London

The statue of James Henry Greathead is a renowned monument erected in 1994, in Cornhill, London. This structure showcases Mr. Greathead carrying a coat over his arm and reading a piece of paper, in an attempt to honor the man for his work on the London “Tube.” Unknown to many visitors, however, this statue is actually a ventilation vent for the city’s underground rail.

The statue of James Henry Greathead was unveiled in 1994 at Cornhill, London, to honor the man for his work on the London “Tube,” the subway system. Sculpted by James Butler, this statue portrays Mr. Greathead studiously reading a set of building plans.

He is also seen wearing a wide-brimmed hat that covers his face in shadow and has an overcoat draped over his arm. Unknown to many visitors, however, this statue is actually a cover for the Bank Underground Station ventilation shaft. 

After the King’s Cross fire in November 1987, engineers recommended that safety improvements be made to the ventilation system of the underground railway.

Initially, it was decided that a vent would be placed directly in front of the Royal Exchange, but concerns soon arose that this would hamper the area’s aesthetic beauty. As a compromise, this ingenious statue of James Henry Greathead was established at the spot, where it continues to attract many visitors. (1, 2)

10 Krupp Control Bunker, Germany

The Krupp Control Bunker was built during World War II as part of a decoy site that would protect the Krupp factory in Germany. It was constructed 10 kilometers from the original factory and had dummy buildings lit by fires and light arrays to attract the Allies. The structure successfully remained undetected until 1943 when RAF bombers rightly identified it.

During World War II, since the Krupp steelworks factory was crucial to the German war effort, the government decided to safeguard it with a decoy site. This site was built about ten kilometers away from the original factory and was called the “Krupp Control Bunker.”  

Apart from the bunker, the decoy site also had railway lines, diesel locomotives that drove around aimlessly, empty gasometers, fake industrial buildings, and light arrays that would come on at night. The bunker was crucial in controlling the lights and other structures at this site, in the hopes that it would fool Allied pilots. 

But in 1943, RAF pilots realized that this was only a decoy, leading to the original factory sustaining some extensive bombings. The factory was then completely destroyed in January 1945, and the decoy site was eventually dismantled. Today, the control bunker is the only remaining reminder of this site. (Source)