Shoppers wrestle over a television as they compete to purchase retail items on “Black Friday” at an Asda superstore in Wembley, north London November 28, 2014. Britain's high streets, malls and online sites were awash with discounts on Friday as more retailers than ever embraced U.S.-style “Black Friday” promotions, seeking to kickstart trading in the key Christmas period. In the United States the Friday following the Thanksgiving Day holiday is called Black Friday because spending usually surges and indicates the point at which American retailers begin to turn a profit for the year, or go “into the black”. (Photo by Luke MacGregor/Reuters)

In his series “Ballerinas of Cairo”, photographer Mohamed Taher documents Egyptian dancers making the city streets their stage – pirouetting, leaping and posing their way through their country’s sprawling capital. The photos are, at first glance, stunning snapshots of a city’s vibrant culture in motion. (Photo by Mohamed Taher/Ballerinas of Cairo)

Riot police officers in position to crack down on demonstrators during a protest against Venezuelan President Nicolas Maduro, in Caracas on April 20, 2017. Venezuelan riot police fired tear gas Thursday at groups of protesters seeking to oust President Nicolas Maduro, who have vowed new mass marches after a day of deadly unrest. Police in western Caracas broke up scores of opposition protesters trying to join a larger march, though there was no immediate repeat of Wednesday's violent clashes, which left three people dead. (Photo by Juan Barreto/AFP Photo)

A British photographer has captured life at the “edge of the world”. Timothy Allen, best known for his work on BBC's Human Planet, trekked through the freezing Siberian wilderness for 16 days as he joined part of an 800km migration of reindeer in the Yamal-Nenets region – a name that roughly translates to “edge of the world”. The stunning pictures feature the nomadic Nenets tribe, who drink blood to survive in -45°C temperatures. Timothy's epic journey, which will be revealed in an eight-minute documentary on Animal Planet USA, saw him travel across the bleak terrain of the frozen Ob River with the Nenets people in December last year. Here: An empty camp is shown beneath a colourful sky in Siberia, December 2016. (Photo by Timothy Allen/Barcroft Productions)

In this Thursday, January 17, 2019, photo, an Indian tamer reacts as a bull charges towards him during a traditional bull-taming festival called Jallikattu, in the village of Allanganallur, near Madurai, Tamil Nadu state, India. Jallikattu involves releasing a bull into a crowd of people who are expected to hang on to the animal's hump for a stipulated distance or hold on to the hump for a minimum of three jumps made by the bull. The sport, performed during the four-day “Pongal” or winter harvest festival, is hugely popular in Tamil Nadu. (Photo by Aijaz Rahi/AP Photo)

A leader “Rolli” of a yodel group “Schuppel” runs in the snow in front of a farmstead during the “Silvesterchlausen” in the early morning in Urnaesch in the Swiss canton Appenzell Ausserroden on January 13, 2017. (Photo by Michael Buholzer/AFP Photo)

An Indian Air Force person walks carrying a Nepalese child, wounded in Saturday's earthquake, to a waiting ambulance as the mother rushes to join after they were evacuated from a remote area at the airport in Kathmandu, Nepal, Monday, April 27, 2015. The death toll from Nepal's earthquake is expected to rise depended largely on the condition of vulnerable mountain villages that rescue workers were still struggling to reach two days after the disaster. (Photo by Altaf Qadri/AP Photo)

These stunning images reveal the remains of a more than century-old sunken ship that has been preserved beneath freezing Lake Superior. The ship looks almost exactly the same as it did the day it sunk beneath waves all those years ago. At 60 meters long (approximately 198 feet), the «Gunilda» sunk after it struck some rocks and was not saved. Now, these stunning images have been captured 107 years after the sinking when a small group of divers revisited the vessel. (Photo by Becky Kagan Schott/Caters News Agency)