The World's Most Secret Places

What lies behind the doors we are forbidden to open?

In an age when satellites can photograph almost every corner of the planet and information travels around the world in seconds, there are still places most of us will never be allowed to enter. Some are protected by armed guards and razor wire. Others are hidden beneath mountains, isolated by oceans or surrounded by extraordinary levels of government secrecy.

Some protect military technology and intelligence operations. Others safeguard priceless resources or isolated communities. And some have remained so secretive for so long that the rumours surrounding them have become almost as famous as the places themselves.

THE WORLD'S MOST SECRET PLACES takes you on a fascinating journey inside the stories of ten of the most restricted, mysterious and heavily protected locations on Earth.

Travel deep into the Nevada desert to AREA 51, the classified American testing facility that became the centre of decades of UFO speculation. Discover the genuine secret aircraft programmes conducted at Groom Lake and explore how Cold War secrecy helped create one of the greatest conspiracy legends of modern times.

Journey across the Bay of Bengal to NORTH SENTINEL ISLAND, home to one of the world's most isolated peoples. Here, outsiders are kept away not to conceal a military secret, but to protect a community that has resisted sustained contact with the outside world.

Travel north to the frozen Arctic wilderness of Svalbard, where a vault buried inside a mountain safeguards backup samples of the world's crop diversity. Often called the "Doomsday Vault", the SVALBARD GLOBAL SEED VAULT represents an extraordinary insurance policy for humanity's agricultural future.

Explore DIEGO GARCIA, the remote Indian Ocean island transformed into a strategically important military base and surrounded by decades of political controversy. Then enter the secretive world of MOUNT WEATHER, the American facility associated with continuity-of-government planning and preparations for catastrophes capable of crippling Washington.

In the Australian Outback stands PINE GAP, the joint Australian-American intelligence facility whose distinctive white radomes conceal sophisticated technology connected with satellites, surveillance and global intelligence gathering.

Behind the walls of Vatican City lies another kind of restricted world. The VATICAN APOSTOLIC ARCHIVE contains centuries of extraordinary historical records, yet its former name-the Vatican Secret Archives-helped inspire countless theories about documents supposedly hidden from humanity.

In Russia, MEZHGORYE AND MOUNT YAMANTAU present a very different mystery. What lies beneath this enormous mountain in the southern Urals? Official information has remained limited, while reports of underground construction and military activity have fuelled decades of speculation.

Then there is FORT KNOX. The United States Bullion Depository is perhaps the most famous secure building on Earth, protecting a vast quantity of America's gold bullion behind formidable layers of security. Very few outsiders have ever been permitted through its doors, ensuring that rumours about what really lies inside have never entirely disappeared.

Finally, travel to the English countryside and RAF MENWITH HILL, where enormous white radomes rise above the Yorkshire landscape. Closely associated with communications, intelligence gathering and the UK-US security relationship, it is one of Britain's most distinctive and intriguing restricted installations.

But THE WORLD'S MOST SECRET PLACES is not a catalogue of conspiracy theories.