File photo taken on July 24, 2011 shows the scenery of karst landform in Dacai Township under Maonan Autonomous County of Huaijiang, south China's Guangxi Zhuang Autonomous Region. The World Heritage Committee on Monday inscribed an extension of South China Karst, a natural World Heritage Site since 2007, into the UNESCO's World Heritage List. (Photo by Wang Xiufa/Xinhua)

A monkey licks ice during the annual “monkey buffet” in Lopburi province, some 150 kms north of Bangkok on November 24, 2013. More than 2,000 kilos of fruits and vegetables were offered to the monkeys during the annual festival to help promote tourism in the area. (Photo by Pornchai Kittiwongsakul/AFP Photo)

Alphajet aircraft draw a heart-shaped message in the sky during the 2010 presentation show of the French aerobatics team Patrouille de France, over the French city of Salon-de-Provence. (Photo by Gerard Julien/AFP Photo)

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)

Meet the star students of orangutan school – the unique rehab centre where orphaned apes are taught how to climb trees and survive in the wild without their mum and dad. (Photo by Caters News)

Jorge, an immigrant from Mexico, exits a subway station dressed as the Sesame Street character Elmo in Times Square, New York July 30, 2014. Elmo and Cookie Monster have long delighted young viewers on TV's “Sesame Street”, but the recent antics of New York street performers dressed as the beloved characters have drawn the ire of city officials and now the show's producers. Sesame Workshop, which owns the rights to Big Bird, Ernie and the assorted puppet monsters on the 45-year-old program, said on July 29, 2014 it was drafting plans to stop performers who dress up as the characters from appearing in Times Square, where they pose for photos with tourists and then demand tips. (Photo by Eduardo Munoz/Reuters)

Members of national folklore and ethnographic groups and employees of a museum-preserve participate in the reconstruction of daily life and traditional holidays celebrated by indigenous population of the Republic of Khakassia during a demonstration for visitors outside a traditional wooden yurt near Kazanovka village, southwest of the city of Abakan, Russia, July 24, 2015. (Photo by Ilya Naymushin/Reuters)

In this September 1, 2015 photo, street artists Jenaro de Rosenzweig, left, and Alejandro Revilla pose for a portrait behind a restaurant's window covered with a mural by artist Francisco Munoz, signed with his artist's name below, in the Roma Norte neighborhood of Mexico City. Rosenzweig and Revilla founded the “Street Art Chilango” cooperative in March 2013, which is filling neighborhoods with public art by local street artists. (Photo by Rebecca Blackwell/AP Photo)