Beyond Borders

National Geographic goes beyond the controversy and political wrangling of illegal immigration to see the real-world battles being waged by the men and women responsible for securing our borders. Every day, they intercept an illicit flow of narcotics, money and weapons headed both north and south across the border. The risks have never been higher, with the violence of the Mexican drug wars a stone's throw from U.S. soil and criminals armed with increasingly sophisticated technology challenging the most rigorous countermeasures.

Professor Alice Roberts reveals how scientists are unearthing the evidence for cataclysmic events in the past and their disastrous consequences. From wars to earthquakes and floods to famines – these are the events that have helped shape our modern world. In each episode, Alice takes viewers on a journey across Europe and North Africa to discover epic sites and landmarks - fabulous cities abandoned, battlefields long forgotten and sophisticated civilisations toppled and lost to the mists of time. To our ancient ancestors, suffering these catastrophic events, it must have seemed they were cursed but science is now exploding those myths and re-writing history.

In 1795, he was an unpaid general consumed with ambition. In 1816, he was a bitter exile on the remote island of St. Helena. In the years between, he was the most powerful man on earth.

In the heart of central Europe are some of the world's most impenetrable military strongholds. In France, 160 megastructure fortresses still line the country's borders 3 centuries after they were constructed. As solid as ever, how did they withstand attack after attack? Was the secret in their materials? Their shape?