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)

A woman wears roller skates with lights on the bottom at Rich City Skate in Richton Park, Illinois, January 12, 2015. A handful of decades-old skating venues put Chicago at the center of a vibrant African-American subculture of urban roller skate dancing that stretches from Atlanta to Detroit and from Los Angeles to New York. While mainstream roller skating has been on a long decline, a new generation of skaters travel a circuit of rinks around the country to compete and show off their moves. (Photo by Jim Young/Reuters)

Measuring just five feet at its widest point, the ultra-thin home was unveiled in the Polish capital of Warsaw on Sunday, October 21, 2012. Photo: The Keret House is squeezed into the space between two apartment buildings in Warsaw. There's a four-inch gap between the apartment buildings to either side. A perforated steel facade was used to allow in more light. (Photo by Andrea Meichsner/The New York Times)

A squid in the Red Sea. Underwater photographer Andrey Nekrasov, 42, photographed bigfin reef squid in the pitch black Red Sea putting on an extraordinary light show when the sun goes down. (Photo by Andrey Nekrasov/Medavia/ABACAPress)

A group of colourful dancers from the Kumari Shiksha Dance Institution light colourful clay lamps in preparation to celebrate Diwali during the two day Diwali (Festival of Lights) Hindu festival celebrations at the old Drive-Inn in Durban, on October 19, 2019. The two-day festival attracts over 100,000 visitors. The festival celebrations include, parading of floats, chariots, singing of devotional songs, dances, games, face painting, food stalls of vegetarian food, clothing, display of toys and jewellery. Young people also get the opportunity to showcase their cultural and spiritual talents. A billion Hindus worlwide will officially celebrate Diwali on 27 October 2019. (Photo by Rajesh Jantilal/AFP Photo)

Two women lighting cigarettes on a tennis court in Essex, England circa 1930's. (Photo by Keystone View/FPG/Getty Images)

Fireworks light up the skyline over Sydney Harbour during the midnight fireworks session as Sydney Celebrates New Year's Eve with the theme of “Time To Dream” on on January 1, 2012 in Sydney, Australia. (Photo by Ryan Pierse/Getty Images)