A man performs ablution using water at an old fountain before performing prayers in the old city of Algiers Al Casbah, Algeria December 3, 2015. The Algiers Casbah is a UNESCO World heritage site that includes the Sidi Ramdane mosque and former fortress, 10 centuries old. Decay from the passing years, as well as earthquake damage in 2003, leads some to consider a move to modern apartments with financial backing from the government. Others refuse to leave a neighbourhood they have called home for decades. (Photo by Zohra Bensemra/Reuters)

Visitors look at an artwork “Hierarchy of Prosperity” created by Indonesian artist Eko Nugroho during the VIP preview of the art fair “Art Basel” in Hong Kong, Tuesday, March 22, 2016. A set of gold-plated metal cubes, tapestries embroidered by unknown North Korean artisans and bales of cardboard waste are among the highlights of the Art Basel Hong Kong fair opening this week. (Photo by Kin Cheung/AP Photo)

A juvenile leopard cat, seized by authorities during an anti-smuggling operation, is seen past suspected smugglers during a press conference announcing the seizure of trafficked exotic animals in Surabaya on March 27, 2019. Indonesian authorities said March 27 they had seized five komodo dragons and dozens of other animals being sold on Facebook, as the country battles to clamp down on the illegal wildlife trade. (Photo by Juni Kriswanto/AFP Photo)

A woman, covered in coloured powder, takes part in the 2019 Colour Run, a 5 km run around the Luzhniki Olympic Complex, in Moscow, Russia on June 02, 2019. (Photo by Sefa Karacan/Anadolu Agency/Getty Images)

Hundreds of pumpkins lie on a field near Frankfurt, Germany, after sunset on Wednesday, October 16, 2019. The autumn vegetable heralds the approach of halloween. (Photo by Michael Probst/AP Photo)

Students stand on the roof of a wooden boat as haze blankets the Musi River while they travel to school in Palembang, on Indonesia's Sumatra island, September 10, 2015. Indonesia is investigating 10 firms over worsening forest fires that have created a blanket of smog over Southeast Asia, threatening them with sanctions if they are found responsible, a government minister said on Tuesday. The thick haze from Indonesia's Sumatra and Kalimantan islands has forced the repeated cancellation of flights in the area and pushed air quality to unhealthy levels in neighbouring Singapore and Malaysia. (Photo by Reuters/Beawiharta)

Children wearing uniforms hold toy guns during a military parade game on China's National Day, at Beyou World, a centre children where can experience different kinds of professions, in Beijing, October 1, 2015. (Photo by Reuters/Stringer)

Contestants of a tattoo competition pose for photographs at the China TATTOO convention in Nanning, Guangxi Zhuang Autonomous Region, China, October 24, 2015. The annual convention was held in Nanning from October 23 to 25 this year. (Photo by Reuters/Stringer)