The 26th annual National Geographic Traveler Photo Contest is now accepting submissions. Official categories include: “Travel Portraits”, “Outdoor Scenes”, “Sense of Place” and “Spontaneous Moments”. The contest is accepting entries until June 30. Photo: “Forest lights”. Aurora Borealis over the forest of the Pyhae Luosto National Park, Finland. (Photo and caption by Nicholas Roemmelt/National Geographic Traveler Photo Contest)

This composite image shows a sequence, from bottom left to top left, of the moon's transition during a total lunar eclipse on April 15, 2014 in Miami, Florida. People in most of north and south America should be able to witness this year's first total lunar eclipse, which will cause a “blood moon” and is the first of four in a rare Tetrad of eclipses over the next two years. (Photo by Joe Raedle/Getty Images)

“Artist Paula Swisher has come up with a quirky way of lessening the stress of household bills - by doodling highly intricate birds on each one. Swisher, 37, has drawn hundreds of birds in her lifetime and puts her love of ornithology down to the nature walks she went on as a youngster. Looking for work during the recession, she began sketching birds on the inside of books, seeing the practice as a creative way to mutate the pages into something fresh. But now she's made the transition from books to bills – while admittedly making a playful commentary on the predatory banking businesses”. – Caters News. (Photo by Paula Swisher/Caters News)

South Korean prostitutes hide their identities as they participate in a rally on September 22, 2005 in Seoul, South Korea. Prostitutes rallied against government law aimed at the s*x industry. (Photo by Chung Sung-Jun/Getty Images)

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)

British singer Cheryl Fernandez-Versini aka Cheryl Cole arrives for the screening of “Ma Loute” (Slack Bay) during the 69th annual Cannes Film Festival, in Cannes, France, 13 May 2016. (Photo by Sebastien Nogier/EPA)

Participants wear traditional clogs as shepherds lead their sheep through the center of Madrid, October 28, 2012. (Photo by Andres Kudacki/Associated Press)

A dejected German Grenadier carrying a machine gun on his shoulder in front of a building on fire during the German retreat in Russia. (Photo by Keystone/Getty Images). 1944