A boy runs with a burning barrel soaked in tar at the annual Ottery St Mary tar barrel festival on November 5, 2015 in Ottery St. Mary, England. The tradition, which is over 400 years old, sees competitors (who must have been born in the town to take part) running with burning barrels on their backs through the village, until the heat becomes too unbearable or the barrel breaks down, starting with junior barrels carried by children and continuing all evening with ever larger and larger barrels. The event, which has been threatened with closure on previous years due to increasing public liability insurance costs, raises thousands of pounds for charity and attracts spectators from around the world. (Photo by Matt Cardy/Getty Images)

“Kids of Sapa”. Four little beautiful Hmong girls from Lao Chai Village, near Sapa, Vietnam. (Photo and caption by Felipe Hanower/National Geographic Traveler Photo Contest)

Pod of dolphins surf effortlessly through the waves in the wild traveling at speeds up to 20 mph. (Photo by Greg Huglin)

Capturing the true essence of Christmas, Lapland is the perfect place to take your family for the holiday period. Situated in the arctic regions of northern Sweden, Finland and Norway, there are a villages in each country around where you can enjoy the full festive experience.

On the western side of Mount Hood lies the longest glacier cave system in the contiguous United States. In 2012, these caves were mapped to a combined length of 7,166.8 feet by cave explorers Brent McGregor and Eddy Cartaya. Currently, the total passage length is hundreds of feet less. Glaciers are frozen rivers; they are always moving and changing... (Photo and caption by Josh Hydeman)

A helicopter is silhouetted by glowing embers as it makes a water drop at the “Old Fire”, which burned in Calabasas, California, U.S., June 4, 2016. (Photo by Gene Blevins/Reuters)

A photographer has captured these eerie images showing the scale of some of Britain's deepest darkest wonders. Mike Deere, from Reading, heads to daunting locations such as abandoned mine shafts, miles of sewer tunnels that snake underneath London and even disused cooling towers. Photo: This incredible picture was taken at the Box Freestone Mine, in Wiltshire. Mike revealed that even experienced map readers would struggle to navigate their way around the seemingly endless tunnels that he and his friends visit. (Photo by Mike Deere/Caters News)

With the humpback calving season drawing to a close, here’s a look at some of Rita Kluge’s distinctive marine photos from the south Pacific. The Sydney-based photographer fell in love with whales after witnessing southern rights from the New South Wales coastline as they travelled to and from their feeding grounds in the Antarctic. She has since been to Tonga, where humpbacks breed and calf in winter months, to photograph them in the water. (Photo by Rita Kluge/The Guardian)