People walk under Australia's iconic landmark Harbour Bridge in Sydney on April 3, 2019, as heavy fog blankets the city. Low visibility due to heavy fog affected traffic in the city and caused flight delays at the Sydney airport. (Photo by Saeed Khan/AFP Photo)

A voodoo believer, dressed as "Gede", a spirit of voodoo, sits on the cross of Baron Samdi during celebrations at the cemetery of Port-au-Prince, Haiti, November 1, 2016. Voodoo believers and devotees offer candles, alcohol and food. The Day of the Dead is celebrated on the first two days of November during All Saints and All Souls Day. (Photo by Andres Martinez Casares/Reuters)

Costumed participants are seen during an Irish tradition of Hunting of the Wren festival held every St. Stephen's Day in Dingle, Ireland, December 26, 2016. Wren Day, also known as Wren's Day, Day of the Wren, or Hunt the Wren Day is celebrated on 26 December, St. Stephen's Day. The tradition consists of “hunting” a fake wren and putting it on top a decorated pole. (Photo by Clodagh Kilcoyne/Reuters)

Children play with weapons during Children's Day celebration at a military facility in Bangkok, Thailand January 14, 2017. (Photo by Jorge Silva/Reuters)

Cadets from the National Cadet Corps (NCC) celebrate after being awarded the first position in the best marching trophy competition during the Republic Day celebrations in the northern Indian city of Chandigarh January 26, 2015. (Photo by Ajay Verma/Reuters)

Pedestrians walk past a truck with a giant Soviet Red Army hat seen on it, an installation created by Russian artist Vasily Slonov, during the annual “Winter Virage” motor sports festival dedicated to the Defender of the Fatherland Day on the embankment of the Yenisei River in Russia's Siberian city of Krasnoyarsk, February 23, 2015. (Photo by Ilya Naymushin/Reuters)

Students feed fruit to an elephant during Thailand's National Elephant Day in the ancient Thai capital Ayutthaya March 13, 2015. Thais honoured the elephant on Friday with special fruits and Buddhist ceremonies across the country to pay homage to their national animal. (Photo by Athit Perawongmetha/Reuters)