For thousands of years, the purpose of Stonehenge has remained a mystery but now archaeologists have uncovered a theory to explain this architectural riddle.
Two researchers explore the world's tallest living trees.
Following a single wolf over the course of its life in Yellowstone National Park.
Following the food chain to reveal the true nature of the northwest Hawaiian Islands.
Bryan Fry and Dr. Sean Bush try to discover why snakebite victims are experiencing strange symptoms.
A new generation of warriors is driven by a goal to rebuild the Montana prairie, restore its wildlife and bring back the majesty of America's Serengeti.
A select few Vikings carried the ultimate weapon of their time, the feared Ulfberht sword.
Archaeologist Jeff Rose goes on a journey to understand how the story of Noah's Ark and the biblical flood may have been influenced by the power of water.
Meat-eating dinosaurs in China; reconstructing original color from fossilized feathers.
Unlocking Florence's city secrets; the birthplace of the Italian Renaissance.
The latest in scientific evidence reveals how cats set off on a journey to conquer the world.
Researchers zero in on what separates humans from our closest living relatives.
In Papua New Guinea, anthropologists and researchers trek through caves, villages and mountains to uncover clues about the ancient tradition of human mummification.
After finding strands of human hair buried in Greenland's permafrost, scientists are attempting to reconstruct the identity of a Stone Age human being through nothing but his ancient locks.
The secrets of Machu Picchu.
The oil spill and its impact on wildlife; rescue teams try fixing the toxic mess.
Phil Manning explores members of the dinosaur family.
Scientists explore ancient crocodiles.
A team of scientists in the year 2210 and the collapse of modern society.
An Italian forensic archaeologist unearths a vampire tomb and uses the latest forensic science to discover the truth.
An underwater journey to the strange world of amazing and rarely seen creatures.
Journey deep into the hidden world of whales.
What is triggering the attacks hippos are making on humans.
Explorer Robert Ballard dives into the belly of the submerged Thera volcano.
How the moose's survival skills have allowed it to flourish.
A profile of the strongest land-dwelling carnivores on earth.
Investigators are trying to discover what agent of destruction wiped the mammoths off the face of the earth.
A Texas community wages war against an unrelenting species of fire ants.
Biologists are concerned that the growing number of pythons is threatening the native wildlife in the Everglades.
Mummies with Caucasian features were found buried in a Chinese desert.
The challenges of building a high-tech science facility in Antarctica.
The engineering and hunting abilities of the great white shark.
Wild bonnet macaques thrive in the cities of southern India.
Scientists and conservationists work to protect endangered species and their environments.
Sheer size has made the Mayan city of Teotihuacan difficult to excavate.
Baikonur Cosmodrome, the oldest and largest space facility.
Scientists attempt to capture images from inside the vortex of a tornado.
Inside the world of Sumo wrestling.
Discover the engineering and ambush tactics of lions and tigers.
The mysterious black caiman in the heart of the Amazon.
In the center of Beijing lies their new stadium in the shape of a bird's nest.
Forensic evidence that bring us closer to understanding the death of a 5,000 year old body.
The likely impact on Los Angeles if a major earthquake occurred.
Australia is being invaded by killer toads with a deadly toxin.
Researchers follow emperor penguins and see the world from their perspective.
Dire Wolves, largest known "Canid's" in North America.
Examining the skeletal structures of the short-faced bear.
In prehistoric times, the king of the cats was not the lion, but the cat.
The rise of one of the world's greatest and most mysterious civilizations.
The Hyenas' daily struggles, hunting lives, and their devotion to their mothers.
The supreme agility, adaptability and witty mind of the rat.
Vipers, one of natures cold-blooded success stories.
Archaelogists go in search of Egypt's fabled past.
Kamchatka is home to 240 volcanos, 29 of which are still active.
The honey badger, a fierce carnivore with a sweet tooth.
Searching for an Adam from whom all humans are descended.
In the Great Bear Rainforest, wildlife coexists as nowhere else on earth.
Giza Plateau; reconstruction of the world of the Great Pyramids.
Jane Goodall's mission of saving chimpanzees.
Human settlement and war have devastated the environment around the Holy Land.
With strict hunting restrictions, cougars have been brought back from near extinction.