Carlsbad Caverns are located in the Chihuahuan Desert of southern New Mexico, within the Carlsbad Caverns National Park. There are more than 100 caves. The Natural Entrance is a path into the namesake Carlsbad Cavern. Stalactites cling to the roof of the Big Room, a huge underground chamber in the cavern.

Andrew Marr sets off on an epic journey through 70,000 years of human history. Using dramatic reconstructions, documentary filming around the world and cutting-edge computer graphics, he reveals the decisive moments that shaped the world we live in today, telling stories we thought we knew and others we were never told." Starting with our earliest beginnings in Africa, Marr traces the story of our nomadic ancestors as they spread out around the world and settled down to become the first farmers and townspeople. He uncovers extraordinary hand-prints left in European caves nearly 30,000 years ago and shows how human ingenuity led to inventions which are still with us today. He also discovers how the first civilisations were driven to extremes to try to overcome the forces of nature, adapting and surviving against the odds, and reveals how everyday life in ancient Egypt had more in common with today's soap operas than might be imagined.

In this series Professor Iain Stewart tells a stunning new story about our planet. He reveals how the greatest changes to the Earth have been driven, above all, by plants. In this first episode Iain journeys from the spectacular caves of Vietnam to the remote deserts of Africa. He sees how plants first harnessed light from the sun and created our life-giving atmosphere. He uncovers the epic battle between the dinosaurs and the tallest trees on the planet. And, using remarkable imagery, he shows plants breathing - and for the first time talking to each other.

The documentary series reveals the extraordinary riches and wonders of the Polar Regions that have kept people visiting them for thousands of years. Today, their survival relies on a combination of ancient wisdom and cutting-edge science. Most Arctic people live in Siberia, either in cities like Norilsk - the coldest city on earth - or out on the tundra, where tribes like the Dogan survive by herding reindeer, using them to drag their homes behind them. On the coast, traditional people still hunt walrus from open boats - it is dangerous work, but one big walrus will feed a family for weeks. Settlers are drawn to the Arctic by its abundant minerals; the Danish Armed Forces maintain their claim to Greenland's mineral wealth with an epic dog sled patrol, covering 2,000 miles through the winter. Above, the spectacular northern lights can disrupt power supplies so scientists monitor it constantly, firing rockets into it to release a cloud of glowing smoke 100 kilometres high. In contrast, Antarctica is so remote and cold that it was only a century ago that the first people explored the continent. Captain Scott's hut still stands as a memorial to these men. Science is now the only significant human activity allowed; robot submarines are sent deep beneath the ice in search of new life-forms, which may also be found in a labyrinth of ice caves high up on an active volcano. Above, colossal balloons are launched into the purest air on earth to detect cosmic rays. At the South Pole there is a research base designed to withstand the world's most extreme winters. Cut off from the outside world for six months, the base is totally self-sufficient, even boasting a greenhouse.

A documentary by Werner Herzog, who gained exclusive access to film inside the Chauvet caves of Southern France and captures the oldest known pictorial creations of humanity. Some of them were crafted as much as 32,000 years ago. The film consists of images from inside the cave as well as of interviews with various scientists and historians. Also includes footage of the nearby Pont d'Arc natural bridge.

The Cave of Swallows in Mexico is a 400m vertical shaft, deep enough to engulf the Empire State Building. The Lechuguilla cave system in the USA is 193km long and 500m deep with astonishing crystal formations hanging from its chambers. Although often overlooked, caves are remarkable habitats with equally bizarre wildlife. Cave angel fish cling to the walls behind cave waterfalls with microscopic hooks on their flattened fins. Cave swiftlets navigate by echo-location and build nests out of saliva. The Texas cave salamander has neither eyes nor pigment. Unique access to a hidden world of stalactites, stalagmites, snotites and troglodytes brings a wealth of surprises.