1. Area 51
Area 51 is a United States Air Force facility in Southern Nevada. The primary purpose of the base is unknown. According to some reports its used for development and testing of aircraft and weapons. According to some conspiracy theories it held UFOs or maybe even actual aliens.
2. RAF Menwith Hill
RAF Menwith Hill is a Royal Air Force base in England. It provides intelligence services to the United Kingdom and the United States of America.
3. Room 39
Room 39 is based on North Korea and is a secret North Korean government organization believed to be involved in counterfeiting, productions of drugs and international insurance frauds.
4. Snake Island (Ilha da Queimada Grande)
Snake is a 43-hectare island off the coast of the Brazil. The Island houses 1 snake every square metre.
5. Vatican Secret Archives
The Vatican Secret Archives is located in Vatican City.The Vatican Secret Archives contain 84 km of shelving.
6. North Sentinel Island
North Sentinel Island is one of the Andaman Islands. A group of people called Sentinelese live on the North Sentinel Island. Their population is between 50 and 400 individuals and are among the last people to remain virtually untouched by the modern world.
7. Metro-2
Metro-2 in Moscow, Russia is believed to be secret underground metro system for top government officials and the Russian secret service.
8. Mezhgorye Town
Mezhgorye is closed to town in Russia and is been permanently closed by the Russian Government.
9. Mount Weather
The Mount Weather Emergency Operations Center in Virginia.
10. Surtsey Island
Surtsey is a volcanic island located in the southern coast of Iceland is arguably the world’s most untouched natural habitat.