Visitors view Patricia Piccinini's “The Embrace” artwork during the “You Know Who” exhibition at the Abdulmecit Efendi mansion in Istanbul, Turkey, 27 September 2022. The exhibition, which by the organizers is described as questioning “the representation of the unknown in contemporary art, based on the symbolic world of the supernatural and unknown in the Byzantine period”, is shown from 20 September until 11 December 2022. (Photo by Erdem Sahin/EPA/EFE/Rex Features/Shutterstock)

Gers, traditional Mongolian tents, are seen on a hill in an area known as a ger district in Ulan Bator June 26, 2013. Approximately 60 percent of the population of Ulan Bator live in settlements known as ger districts and in many cases residents have limited access to basic services such as water and sanitation. According to a 2010 National Population Center census, every year between thirty and forty thousand people migrate from the countryside to the capital Ulan Bator. Ger districts in the city have been expanding rapidly in recent years. Mongolia is the world's least densely populated country, with 2.8 million people spread across an area around three times the size of France. (Photo by Carlos Barria/Reuters)

A man walks past the body of a man after he was shot in the head by unknown assailants during a protest in Port-au-Prince, Haiti, Monday, August 22, 2022. (Photo by Odelyn Joseph/AP Photo)

Bella Hadid attends “The Unknown Girl (La Fille Inconnue)” Premiere during the 69th annual Cannes Film Festival at the Palais des Festivals on May 18, 2016 in Cannes, France. (Photo by Alberto Pizzoli/AFP Photo)

Mug shot of De Gracy (sic) and Edward Dalton. Details unknown. Central Police Station, Sydney, around 1920. (Photo by NSW Police Forensic Photography Archive, Justice & Police Museum, Histiric Houses Trust of NSW)

A changing of the honor guard ceremony by the Tomb of the Unknown Soldier in Alexander Garden by the Kremlin Wall in Moscow, Russia on May 29, 2020. (Photo by Vladimir Gerdo/TASS)

A woman looks at the honour guard soldiers marching at the Tomb of the Unknown Soldier by the Kremlin wall, in downtown Moscow, on June 28, 2021. (Photo by Alexander Nemenov/AFP Photo)

A utility worker clears snow by the Tomb of the Unknown Soldier in Alexander Garden during a snowfall in Moscow, Russia on January 28, 2021. (Photo by Vyacheslav Prokofyev/TASS)