Ch. 4 Iris Prize

The Aztecs ruled one of the most powerful civilisations ever seen in the Americas. They were ruthless warriors and ingenious engineers, who conquered a huge territory and built towering pyramids and ambitious civil engineering projects using manpower alone. But after just 200 years their vast empire was wiped out by Spanish invaders, and their cities and monuments were destroyed. Today many of the Aztecs’ secrets lie buried underneath Mexico City. Now archaeologists are digging deeper than ever before to find out who the Aztecs were and how they built their remarkable empire.

Bettany Hughes takes viewers on armchair travels to explore household-name treasures and new finds from across the world.

Beneath soaring mountains and along shimmering shorelines, this series takes in the breathtaking landscape on some of Britain's most scenic railway journeys.

An expert team of engineers use hi-tech explosions and state-of-the-art drilling rigs to tear through solid granite and build an 11-mile underground tunnel, one of the longest in the world.

The world's best shipbuilders join forces to build a state-of-the-art ship that comes equipped with two submarines, and using cutting-edge engineering, it can brave the Arctic Ocean's worst winters and deadliest seas.

An expert team of engineers are using cutting-edge tech and the latest construction methods to build Los Angeles's biggest engineering project ever: a series of brand-new subway lines in durable, earthquake-proof tunnels.

Tory Belleci and Streetbike Tommy meet the expert firefighters who use cutting-edge explosive technology to battle dangerous infernos, and using the latest science, they'll find if the best antidote to fire is more fire.

The skinniest skyscraper in the world will soon become New York's third tallest, and using an innovative, gravity-defying design, this colossal megastructure is breaking all the rules of engineering.

Our universe's stars are dying off faster than new ones are born, and using the latest technology, experts investigate the secrets of the last stars of the cosmos and what this stellar apocalypse means for life on earth.

Earth's journey through the universe is a perilous one, and new discoveries reveal that our planet is heading toward a mysterious area of the cosmos that could eject us out of the Milky Way and into oblivion.