“The Tibetan Mastiff also known as Do-khyi (variously translated as “home guard”, “door guard”, “dog which may be tied”, “dog which may be kept”), reflects its use as a guardian of herds, flocks, tents, villages, monasteries, and palaces, much as the old English ban-dog (also meaning tied dog) was a dog tied outside the home as a guardian. However, in nomad camps and in villages, the Do-khyi is traditionally allowed to run loose at night and woe be unto the stranger who walks abroad after dark”. – Wikipedia

Photo: A man displays a Tibetan Mastiff he raised during the Tibetan Mastiff exposition on April 7, 2007 in Langfang of Hebei Province, China. (Photo by China Photos/Getty Images)

A vegetarian festival devotee gets medical attention after a parade at Jui Tui shrine on September 30, 2014 in Phuket, Thailand. (Photo by Borja Sanchez-Trillo/Getty Images)

Undated handout issued by Take A View of Sunrise at Winnats Pass, Derbyshire, England which won the Visit Britian “You're invited” Award for the best image from an overseas entrant category in this year's Landscape Photographer of the Year Awards. (Photo by Sven Mueller/PA Wire)

A surfer rides a large wave at El Bocal during the Vaca Gigante (Big Cow) giant wave surf competition in Santander, northern Spain December 17, 2016. (Photo by Vincent West/Reuters)

Photographer Pol Kurucz’s vivid collection of photos explores issues faced by black Brazilian women, from political misrepresentation to unrealistic beauty standards. Kolor Collective is a Rio de Janeiro-based creative group that challenges the struggle faced by black women in Brazil through theatrical and provocative art. It was founded in 2015 by Franco-Hungarian photographer Pol Kurucz, who often touches on his own experiences of discrimination to call out sensitive social problems. (Photo by Kolor Art Collective/The Guardian)

A cooling tower is seen under mechanical demolition in Binzhou, Shandong Province, China, July 13, 2016. (Photo by Reuters/China Daily)

Tube passengers take a selfie next to a London underground roundel designed for the launching of the Night Tubes on display at Oxford Circus underground station in London, Britain, 19 August 2016. The long delayed Night Tubes service launched on 19 August. The 24-hour service will operate on Fridays and Saturdays. (Photo by Hannah Mckay/EPA)

This watering hole is the social hub of the veldt; the scrubby grasslands that stretch across Namibia. The scorched earth supports sometimes fragile populations of magnificent wildlife – from endangered predators to plentiful herds of game. But these gentle giraffes and elephants need to be careful: lions don’t sleep at night, they hunt! The spectacular starscape above southern Africa is unchanged since explorers first mapped the continent. The photographer, Pietro Olivetta from Italy, said he had to be patient to capture these shots – but it was worth the wait. (Photo by Pietro Olivetta/Caters News)