The title of Ava DuVernay's extraordinary and galvanizing documentary refers to the 13th Amendment to the Constitution, which reads 'Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States.' The progression from that second qualifying clause to the horrors of mass criminalization and the sprawling American prison industry is laid out by DuVernay with bracing lucidity. With a potent mixture of archival footage and testimony from a dazzling array of activists, politicians, historians, and formerly incarcerated women and men, DuVernay creates a work of grand historical synthesis.

Prepare yourself for an unparalleled sensory experience. Samsara reunites director Ron Fricke and producer Mark Magidson, whose award-winning films Baraka and Chronos were acclaimed for combining visual and musical artistry. Samsara explores the wonders of our world from the mundane to the miraculous, looking into the unfathomable reaches of humanity's spirituality and the human experience. Neither a traditional documentary nor a travelogue, Samsara takes the form of a nonverbal, guided meditation.

Michael Moore examines the current state of American politics, particularly the Donald Trump presidency and gun violence, while highlighting the power of grassroots democratic movements. Fahrenheit 11/9 finds the filmmaker in fine fighting form, delivering a political call to action that ranks among his most effective works.

Academy Award-winning director Alex Gibney (Taxi to the Dark Side) masterfully explores the fall of the disgraced cycling champion following the 2009 Tour de France, making use of his extraordinary access to attain rare interviews with former teammates, alleged doping mastermind Dr. Michele Ferrari, and Armstrong himself. What was Lance Armstrong thinking? For years, after seizing international fame as the cancer survivor who won seven Tour de France titles, he fiercely denied accusations that he used performance-enhancing drugs. He used his power to aggressively litigate journalists and publicly humiliate former friends who claimed otherwise. His deceit finally cracked in January 2013, when he admitted guilt to Oprah Winfrey in a television interview that critics decried for only scratching the surface. Academy Award-winning director Alex Gibney approaches Armstrong with unique and extraordinary access. In 2009, Gibney was commissioned to make a film about Armstrong's return to the Tour de France, four years after the racing champion had declared retirement. That race would later stir up devastating evidence in the case against Armstrong. But Gibney came away from the experience unable to reconcile the discrepancy between doping allegations and Armstrong's emphatic denials. Then, post-Oprah, Gibney went back to Armstrong for new interviews to extract a more detailed account of his double life. In The Armstrong Lie, Gibney masterfully explores the complexities of the case, interweaving the dramatic action of the 2009 Tour de France, when Armstrong found himself unexpectedly competing against his own teammate Alberto Contador. Gibney attains rare interviews with Armstrong's former teammates and alleged doping mastermind Dr. Michele Ferrari. The film also raises troubling questions about the process of doping regulation. Recently, when asked to give advice to documentary filmmakers, Gibney responded with a motto exemplified by this film: "Embrace contradictions."

A group of brave individuals risk their lives to save the last of the world's mountain gorillas; in the midst of renewed civil war and a scramble for Congo's natural resources." Virunga National Park in the Congo is a place of unique natural beauty. It is the home to a plethora of wonderful animals and vegetation but as is so often the way, it has several serious problems that threaten it. It's the location of human violence, corruption and exploitation. The disasters that specifically loom are two different groups, the M23 and SOCO International. The former are a violent rebel force who engages in an ongoing civil war with the Congolese government and the latter are a British energy company who specialise in oil exploration. Both M23 and SOCO invade the park in their own ways and neither seems very interested in the laws that have been set up to protect the flora and fauna that exist there, far less the people who live there. It seems hardly surprising in the case of M23, as they are a paramilitary organisation who can hardly be expected to be concerned with such things but it is the more legitimate big business SOCO who seem more worrying if anything. We discover in fact that they have been involved in a bribery campaign, utilising M23 as enforcers. It's a very murky situation where big money walks all over an impoverished nation and disregards a natural space that they can see no value in in their pursuit of financial profit.

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.