CASTLE combines colorful animation with live-action documentary sequences to tell the story of a 13th-century Welsh castle. Author David Macaulay, who wrote and illustrated the best-selling book of the same title, leads viewers on a castle tour, explaining its cultural and sociological significance and its architectural design. Detailed animation dramatizes the building of the castle and portrays the lifestyle of the early inhabitants.

People can actually become more fit, both physically and mentally, as they grow older. Join Dr. Henry Lodge as he dispels the myths of American aging and explains the new science of aging. Viewers will learn how to take charge of their biology to become functionally younger, more vibrant, purposeful, and dynamic for years to come.

This riveting six part series chronicles the highest award given to military personnel for their extreme bravery, valor and harrowing sacrifices. Learn about the courageous acts performed by the people who fight for American freedom.

When the alarm system at Headquarters is triggered, Olive, Otto, Ms. O, and Oscar must avoid a series of booby traps in order to shut it off.

Quiet time: Big Bird loves to sing and dance and play, but when his Granny Bird tells him it's "quiet time", he's not sure what to do. Fortunately, Oscar, Telly, Rosita, and his other Sesame Street friends have plenty of great ideas, like reading stories, playing quiet games and more. A great preparation for a child's nap time, this special helps Big Bird decide what to do during his "quiet time". Sleepytime songs and stories: Cookie Monster sings...

Explores how ordinary people are utilizing their brain plasticity to create lasting and astonishing changes. From aging to recovery from injury, the frontiers of neuroscience research are proving that our own neuroplasticity holds the key to previously unimaginable and incredible transformations.

"There's a porridge shortage on Sesame Street! Baby Bear and his family are getting ready to hibernate until spring, when there will be porridge again ... but will they be able to get to sleep? Guest star Meredith Vieira talks about the word "hibernate," and it's nap time in Elmo's World. Abby and friends learn to recycle in Abby's Flying Fairy School, while Bert and Ernie fly off on another adventure. Finally, Murray introduces the letter K and the...

Three women at risk of developing Alzheimer's join a groundbreaking study to try to prevent the disease, while sharing their ups and downs, anxiously watching for symptoms, and hoping they can make a difference.

In Smarter Brains, we uncover the latest research and reveal groundbreaking experiments that are redefining intelligence throughout our lifespan and especially our later years. Smarter Brains shows the amazing science behind our intelligence - how it shapes our experience and enjoyment of the world around us, and how we can change and improve it, regardless of our age.

Astrophysicist Mario Livio, along with a colorful cast of mathematicians, physicists, and engineers, follow math from Pythagoras to Einstein and beyond, all leading to the ultimate riddle: Is math an invention or a discovery? Humankind's clever trick, or the language of the universe? Join Nova for a mathematical mystery tour, a provocative exploration of math's astonishing power across the centuries.