“Kilauea Rules”. The most extreme place we put ours kayakers to paddle till now. Photo location: Big Island, Hawaii. (Photo and caption by Alexandre Socci/National Geographic Photo Contest)

A pangolin carries its baby at a Bali zoo, Indonesia, Thursday, June 19, 2014. The pangolin baby was born on May 31. (Photo by Firdia Lisnawati/AP Photo)

Three prostitutes lean out of a window in Santiago, Chile, in an attempt to entice customers inside, circa 1950. (Photo by Three Lions/Getty Images)

Participants take part in a high-heel race at a Gay Pride party in the central neighborhood of Chueca in Madrid on July 3, 2014. (Photo by Gerard Julien/AFP Photo)

A demonstrator with face painted in the colours of the Palestinian flag protests outside the Israeli Embassy in west London July 26, 2014. Foreign ministers from the United States, Europe and the Middle East called on Saturday for an extension of the 12-hour ceasefire between Israel and Hamas in the Gaza Strip, French Foreign Minister Laurent Fabius said. (Photo by Luke MacGregor/Reuters)

The front wheels of a tractor, pulling a trailer overloaded with sugarcane, are seen lifted off the ground as it passes through the streets of Karor Lan Esan, Pakistan December 6, 2015. (Photo by Caren Firouz/Reuters)

An Israeli spectator watches a giant T-Rex balloon during the Purim parade festival in Petah Tikva, Israel, Thursday, March 24, 2016. The Jewish holiday of Purim commemorates the Jews' salvation from genocide in ancient Persia, as recounted in the Book of Esther. (Photo by Oded Balilty/AP Photo)

Miniature pig “Nueffel” is walked in a park in Hanover, Germany, 14 April 2016. (Photo by Sebastian Gollnow/EPA)