Sixty-six million years ago, an asteroid wiped out the dinosaurs in a fiery global catastrophe. An amazing new trove of fossils reveals how mammals took over, ultimately evolving into the huge array of species, including us, that rule Earth today.

Journey to Florence to discover how Leonardo da Vinci used science, from human dissections to innovative painting techniques, to create his legendary artwork. Learn why Mona Lisa's smile is so captivating - and what it took to create it.

Discover what it was like to be a knight in shining armor and follow the historic manufacturing process. Join master armorers as they re-engineer the Greenwich armor-considered some of the greatest armor ever made-and then put it to the test.

A 3,700-year-old inscribed clay tablet reveals a surprising new version of the Biblical flood story, complete with how-to instructions for assembling an ark. Following the directions, expert boat builders assemble and launch a massive reed boat.

Carved from 100 million pounds of stone, soaring effortlessly atop a spiderweb of masonry, Gothic cathedrals are marvels of human achievement and artistry. But how did medieval builders reach such spectacular heights? Consuming the labor of entire towns, sometimes taking 100 years to build, these architectural marvels were crafted from just hand tools and stone. Many now teeter on the brink of catastrophic collapse.

Stunning new archaeological evidence provides clues about the Egyptians who built the Great Pyramid of Giza -- and how they did it. Join researchers as they delve into the logbook of a work crew and discover how the massive project transformed Egypt.

Discover the ingenious engineering of Beijing's Forbidden City, the power center of imperial China for nearly 500 years. Discover how the design of this vast complex of palaces and temples enabled it to survive centuries of earthquake shocks.

For over 1000 years, chariots thundered across China's battlefields-dominating warfare longer than anywhere else on earth. Now, a series of amazing archaeological findings enable a team of experts to reconstruct and test China's first super-weapon.

Dogs have long been dependable companions by our sides. But it wasn't always that way, and a look at their closest living relative, the wolf, makes it clear why. Researchers reveal how humans tamed fearsome canines over tens of thousands of years, and how modern dog intelligence and behaviors have made them indispensable companions.