The world underground undergoes devastating changes in a post-apocalyptic world. This documentary examines how man-made and natural caverns will evolve over millennia. Geothermal power plants will buckle under the strain of superheated steam. NORAD, America's former nuclear command center, will come under attack from a leaking reservoir. The Naica Crystal Caves in Mexico will grow giant gypsum crystals, while New Mexico’s Carlsbad Caverns will fill...

In the wake of World War II, in a move closely related to the beginnings of the Cold War, the United States of America decided to resume nuclear testing in the Pacific Ocean, on Bikini Atoll in the Marshall archipelago. After the displacement of the local inhabitants, 67 nuclear tests were carried out from 1946 to 1958, including the explosion of the first H-bomb (1952). Bikini Atoll has conserved direct tangible evidence that is highly significant...

In this episode—which includes special guest appearances from The League of Gentlemen’s Reece Shearsmith, Mark Gatiss and Steve Pemberton—we meet a surprisingly charming Stuart highwayman, the captain of the Titanic holds the world’s worst safety briefing, famous writer Mary Shelley pitches the movie of her life, and those violent Vikings show their softer side in a song.

In 55 BC Julius Caesar marched through Europe, crushing the rebellious tribes in the North. In mid-summer he arrived at the mighty Rhine. He was determined to get his legions across to teach the tribes on the other side a lesson, but considered it beneath the dignity of the Roman army to cross the river by boat. Consequently, he ordered his men to build a wooden bridge over a river which was at least 400 meters wide, up to 8 meters deep and flowing...

In a tale of fantastic geographical sweep, Michael Wood conjures up China's first great international age, the Tang Dynasty. From picturesque old cities on the Yellow River he travels to the bazaars of the Silk Road in Central Asia, and on to India in the footsteps of the Chinese monk who brought Buddhist texts to China.

Iraq's 1990 invasion of Kuwait resulted in more than one million troops facing off against each other in the desert of the Persian Gulf. The Allied Coalition's air war, known as Operation Desert Storm, involved the most sophisticated technological weaponry available.

Medieval art historian Alixe Bovey follows the Gough Map to the once-important port town, Sandwich; to Canterbury Cathedral, the resting place of Thomas Becket; and to London, which became one of the most powerful cities of the Middle Ages thanks to the River Thames.

Panama-Pacific International Exposition: Opening day celebrations / crowds at the entrances / pan of Exposition proper / parades on Market Street and Van Ness Avenue / Tower of Jewels / Fountain of Energy / other buildings / day for night shots / submarines / Fun Zone at night / nighttime illumination of buildings showing use of fog machines and special lights / Uncle Sam's submarines. No audio. (13 minutes)

The investigation into the Knights Templar and whether the order continued on in secret well beyond their official end in 1307 takes the team to the ancient city of Acre, where one of the largest tunnel complexes in the world was built centuries ago.

In this program, U.S. ground troops storm the Philippines. In addition, two heroic veterans - an airman forced to bail out over Europe and a sailor who had to abandon ship - recall their terrifying experiences.