Whether serving as Christian church, Islamic mosque, or secular museum, Hagia Sophia and its soaring dome have inspired reverence and awe. For 800 years, it was the largest enclosed building in the world—the Statue of Liberty can fit beneath its dome with room to spare. How has it survived its location on one of the world's most active seismic faults, which has inflicted a dozen devastating earthquakes since it was built in 537?" As Istanbul braces for the next big quake, a team of architects and engineers is urgently investigating Hagia Sophia's seismic secrets. Follow engineers as they build a massive 8-ton model of the building's core structure, place it on a motorized shake table, and hit it with a series of simulated quakes, pushing it collapse—a fate that the team is determined to avoid with the real building

Art critic Andrew Graham-Dixon tells the incredible story of Russian art, its mystery and magnificence and until now a story untold. He explores the origins of the Russian icon from its roots in Byzantium and the first great Russian icon, Our Lady of Vladimir to the masterpieces of the country's most famous icon painter, Andrei Rublev. Both epic and awe-inspiring, and producing brilliant art", nevertheless medieval Russia could be a terrifying place. Criss-crossing the epic landscape, Andrew visits the monastery founded by Ivan the Terrible, where his favourite forms of torture found inspiration in religious art. One man would shine a light into Russia's 'dark' ages - Peter the Great who, surprisingly, took as his inspiration Deptford in South London.

The dome that crowns Florence's great cathedral of Santa Maria del Fiore, the Duomo, is a masterpiece of Renaissance ingenuity and an enduring source of mystery. Still the largest masonry dome on earth, it is taller than the Statue of Liberty and weighs as much as an average cruise ship. Historians and engineers have long debated how its architect, Filippo Brunelleschi, kept the dome perfectly aligned and symmetrical as the sides rose and converged toward the center." More than four million bricks could collapse at any moment -- and we still don't understand how Brunelleschi prevented it. To test the latest theories, a team of U.S. bricklayers will help build an experimental "mini-Duomo" using period tools and techniques.

A 4000-year-old body is found preserved in an Irish peat bog, in Cashel, Ireland. To scientists and historians, it could offer brand new clues to solve an ancient mystery: the hundreds of bodies found mummified in the boglands of Northern Europe. Now, will Cashel Man help prove the theory these Irish victims were ancient kings? And what clues can the bog bodies of Europe offer to explain our ancestors' most macabre tradition - ritual murder? Meanwhile, that question could be answered by the bog itself.

Join the Mars rovers Spirit and Opportunity for an awe-inspiring journey to the surface of the mysterious red planet. Through the eyes of these two intrepid, death-defying rovers, and with NASA scientists and engineers at your side, you’ll see Mars in a way no one ever has before. You’ll feel what it is like to stand on the startling surface of the planet that’s intrigued mankind for eons. And you’ll uncover its ultimate mystery: Is there life on Mars? Roving Mars – it’s the ride of a lifetime.

Horizon uncovers the secret world of our dreams. In a series of cutting-edge experiments and personal stories, we go in search of the science behind this most enduring mystery and ask: where do dreams come from? Do they have meaning? And ultimately, why do we dream? What the film reveals is that much of what we thought we knew no longer stands true. Dreams are not simply wild imaginings but play a significant part in all our lives as they have an impact on our memories, the ability to learn, and our mental health. Most surprisingly, we find nightmares, too, are beneficial and may even explain the survival of our species.