The documentary series reveals the extraordinary riches and wonders of the Polar Regions that have kept people visiting them for thousands of years. Today, their survival relies on a combination of ancient wisdom and cutting-edge science. Most Arctic people live in Siberia, either in cities like Norilsk - the coldest city on earth - or out on the tundra, where tribes like the Dogan survive by herding reindeer, using them to drag their homes behind them. On the coast, traditional people still hunt walrus from open boats - it is dangerous work, but one big walrus will feed a family for weeks. Settlers are drawn to the Arctic by its abundant minerals; the Danish Armed Forces maintain their claim to Greenland's mineral wealth with an epic dog sled patrol, covering 2,000 miles through the winter. Above, the spectacular northern lights can disrupt power supplies so scientists monitor it constantly, firing rockets into it to release a cloud of glowing smoke 100 kilometres high. In contrast, Antarctica is so remote and cold that it was only a century ago that the first people explored the continent. Captain Scott's hut still stands as a memorial to these men. Science is now the only significant human activity allowed; robot submarines are sent deep beneath the ice in search of new life-forms, which may also be found in a labyrinth of ice caves high up on an active volcano. Above, colossal balloons are launched into the purest air on earth to detect cosmic rays. At the South Pole there is a research base designed to withstand the world's most extreme winters. Cut off from the outside world for six months, the base is totally self-sufficient, even boasting a greenhouse.

The episode is a journey through the human gut and the process of turning food into energy to keep the body going. Humans have turned eating into culture, a way to celebrate our roots, to bring us together. But food is really just one thing: Fuel. It's where you get the power to live your life. Even when you're sitting completely still, your body needs a lot of energy to stay on. But nowhere is the need for fuel more apparent than when you push yourself to the absolute limit. And the microbiome, the bacteria living in our gut, plays a great role in all this.

The Fyre Festival was billed as a luxury music experience on a posh private island, but it failed spectacularly in the hands of a cocky entrepreneur. Fyre smolders with agonizing tension when that party in paradise goes awry, but this slickly assembled documentary reserves its greatest horror for damning observations about the dangers of wealth.

Travel writer Simon Reeve embarks upon two long-distance journeys across Turkey, exploring this dramatic and beautiful country that now finds itself at the centre of world events. In this programme, he visits Istanbul and the beaches and crystal clear waters of the Aegean Sea, before ending up at the war-torn border with Syria.
In the region thought to have been the origin of the first vineyards, Simon meets a producer now trying to sell wine in a Muslim country with an increasingly conservative government. In Istanbul, he meets some of the people shaping modern Turkey, from loyal supporters of the nation's controversial and authoritarian president to the master builder constructing one of the world's largest mosques and the notorious billionaire cashing in on a Turkish property boom.
Along Turkey's famous Turquoise Coast, Simon has a taste of luxury at the country's most expensive hotel, but discovers an industry on its knees as war in Syria and deadly terror attacks keep millions of holidaymakers away.

Cooking shows turned the humble garlic bulb into something that's essential to cuisines and into a multi-billion-dollar crop. Every year, humans consume nearly 50 billion pounds of garlic, and most of it comes from one country: China. But a lawsuit raises troubling questions about suppliers.

Schwalmstadt Maximum Security Prison in Germany. Locked up behind the walls of this 12th-century castle are 188 of Germany's worst offenders. The prison is a fortress surrounded by a moat, and houses dangerous criminals, many of whom attend intense therapy sessions.