The “Sarandi” stream, dyed red due to unknown contaminants allege residents, flows into the Río de la Plata on the outskirts of Buenos Aires, Argentina, February 6, 2025. (Photo by Rodrigo Abd/AP Photo)

An undated archive picture shows a dog pulling a Belgian machine gun at an unknown location in northern France. A Viscount in the Armoured Cavalry Branch of the French Army left behind a collection of hundreds of glass plates taken during World War One (WWI) that have never before been published. The images, by an unknown photographer, show the daily life of soldiers in the trenches, destruction of towns and military leaders. The year 2014 marks the 100th anniversary of the start of WWI. (Photo by Collection Odette Carrez/Reuters)

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 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)

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 swarm of starlings flies over the Altare della Patria monument (Unknown soldier) in the city centre of Rome during sunset, on November 27, 2018. (Photo by Vincenzo Pinto/AFP Photo)

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)

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)