High-rise buildings are partly covered by heavy fog at Hong Kong's Victoria Harbour Monday, March 20, 2017. Fog blanketing Hong Kong is common in springtime and may greatly affect shipping and aviation. (Photo by Vincent Yu/AP Photo)

Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

A dark Devon Rex cat is held by its owner during a competition in Bucharest, Romania, Saturday, September 26, 2015. More than 300 cats entered the international feline beauty competition in the Romanian capital. (Photo by Vadim Ghirda/AP Photo)

A worker holds the head of a fox while killing it with electricity for its fur at a fox farm in Nanzhuang village, Shandong province, China, December 11, 2015. There are over 60 households in the village still raising foxes, raccoon dogs and other animals for the fur trade. China is the world's largest fur producer and exporter, according to state media. (Photo by William Hong/Reuters)

A girl attends Friday prayers in front of an army tank in Tahrir Square in Cairo February 18, 2011. Five years ago thousands of protesters took to the streets demanding the end of the 30-year reign of President Mubarak as Egypt became the second country to join the Arab Spring. After weeks of clashes, strikes and protests across Egypt, Mubarak resigned on February 11, 2011. (Photo by Suhaib Salem/Reuters)

In his series of untitled photographs Nobody Claps Anymore, the Mexican-American photographer Alec Dawson portrays ordinary people in their homes in a downbeat, ultra-stylised manner. Staring into space as they watch TV or water the garden, the real-life subjects of photographer hint at vast reserves of boredom and regret. (Photo by Alec Dawson)

Andrew Hepher, Vice President of Lubricants Technology, Shell unveils the Shell Concept Car in Beijing, China, Friday, April 22, 2016. Built as proof of energy efficiency that can be achieved with the latest technologies, Shell unveiled the concept car ahead of the bi-annual Beijing Auto Show where the world's top car manufacturers will showcase their own upcoming products. (Photo by Ng Han Guan/AP Photo)

Catholic faithfuls hold figurines of baby Jesus during a religious procession on Holy Innocents Day in Antiguo Cuscatlan, El Salvador, December 28, 2016. (Photo by Jose Cabezas/Reuters)