A man carries a bag on his back in Guangzhou, Guangdong province, January 26, 2016. According to traffic police, over 2.9 billion trips will be made around China during the 40-day Spring Festival travel rush, which started on January 24. (Photo by Reuters/Stringer)

An Iranian soldier guards two German tourists near the Iranian-Turkish border during World War II. Since the British occupation of Iran, all Axis nationals are being expelled from the country. (Photo by Three Lions/Getty Images). Circa 1941

An armed police officer attends an explosive ordnance disposal training on April 12, 2022 in Nanning, Guangxi Zhuang Autonomous Region of China. (Photo by Yu Haiyang/VCG via Getty Images)

Attendants wait for visitors to the the exhibition entitled “Forging Ahead in the New Era”, showing the country's achievements during his past two terms, at the Beijing Exhibition Center in Beijing on October 12, 2022, ahead of the 20th Communist Party Congress meeting. (Photo by Noel Celis/AFP Photo)

Aerial view of CRH bullet trains setting out ahead of Spring Festival travel rush on January 31, 2018 in Hefei, Anhui Province of China. About 2.98 billion trips will be made during the 40-day Spring Festival travel rush. China will take multiple measures to ensure a smooth Spring Festival travel rush. (Photo by VCG/VCG via Getty Images)

Marianne Brauns jumping a breakwater on the beach, wearing a structured blue swimsuit with white trim. (Photo by Carl Sutton/Hulton Archive/Getty Images). Circa 1950

Tourists walk above a tea plantation in Enshi, Hubei province, December 27, 2015. (Photo by Reuters/Stringer)

A bunker at aformer Swiss artillery fortress called Heldsberg stands near the town of St. Margareten, Switzerland March 22, 2015. Heldsberg fortress, located on the Swiss-Austrian border near the River Rhine and Lake Constance was built from 1938 to 1940 and remained in military use until 1992. Since 1993 it is open to the public as Fortress Museum Heldsberg. (Photo by Arnd Wiegmann/Reuters)