Bulgarian men dance in the icy waters of the Tundzha river during a celebration to commemorate Epiphany Day in the town of Kalofer January 6, 2015. It is believed that the ritual will bring good health to the participants throughout the new year. (Photo by Stoyan Nenov/Reuters)

Every year, in the Rostov region of Russia, a group of 40 young and not so young rural workers compete in the Bison Track Show, or more affectionately known as: Russian Flying Tractor Racing. In front of crowds numbering up to 30,000 people, a series of smoke spilling, monstrous farming machines tear round an 8km mud track, plowing through lakes and dirt mounds, their turbos screaming and tyres scrabbling to find grip.

A retrospective of Garry Winogrand's photography is on display at the Metropolitan Museum of Art in New York. It is the first in 25 years of his work. The show was organized by the San Francisco Museum of Art, and the National Gallery in Washington, DC. Photo: New York, 1965. (Photo by Garry Winogrand/The Estate of Garry Winogrand, courtesy Fraenkel Gallery, San Francisco)

Encyclopedia Britannica editions are seen at the New York Public Library on March 14, 2012 in New York City. Encyclopedia Britannica announced it will be ceasing its print edition of reference books for the first time in its 244-year history to focus solely on digital versions. (Photo by Mario Tama/Getty Images)

Magdalena Neuner poses in front of mammoth figures during a photocall of the German Biathlon Woman Team at the Archeopark on March 10, 2011 in Khanty-Mansiysk, Russia. On the territory of Archeopark are mammoth sculptural compositions, made of bronze. Mammoths lived in Ugra 70-10 thousand years ago and were members of the Pleistocene, or also called 'the mammoth fauna’. The growth figures exceed the natural factor 2-3 times.

A eight-metre-long Whale shark swims with other fish in a worlds' largest tank with its front panel size of 8.2 metre x 22.5 metre at the Okinawa Churaumi Aquarium on February 26, 2010 in Motobu, Okinawa, Japan. Japan's most popular aquarium attracts more than 2.5 million visitors per year. (Photo by Koichi Kamoshida/Getty Images)