A picture rotated 180 degrees shows visitors walking inside an “Upside-down House” attraction at the VVTs the All-Russia Exhibition Center in Moscow, on January 14, 2014. The attraction to experience a new perspective of a house standing upside down was opened first time in Russia, the show organisers said. (Photo by Alexander Nemenov/AFP Photo)

A visitor walks on a giant chalk artwork called “Wasting Time” at the Chalk Urban Arts Festival in Sydney on October 25, 2014. The picture is the biggest 3-D artwork created in Australia by two artists, Leon Keer from Holland and Jenny McCracken from Australia. (Photo by Peter Parks/AFP Photo)

Visitors view the work entitled “Golden Jubilee” by Chinese artist Xin Dongwang at the “Extension and Integration: A Circuit Exhibition In Hubei Of Study on the Modern Chinese Oil Painting” at the Hubei Museum of Art on March 8, 2009 in Wuhan of Hubei Province, China. (Photo by China Photos/Getty Images)

A glass skywalk in Wanyuan, Sichuan province, built along the side of a cliff, is the highest such skywalk anywhere in China on January 31, 2017. Some visitors have been proven to be terrified by the experience had to brace against the wall in fear. (Photo by Chinanew.com/AsiaWire)

A priest is seen looking out of Abuna Yemata church’s only window. Priests cheerfully tell visitors that pregnant women, babies and old people attend Sunday services and no one has fallen off. (Photo by Ethiopia – The Living Churches of an Ancient Kingdom/The American University in Cairo Press/The Guardian)

Visitors walk past sculptures on display as part of the Sculpture by the Sea exhibition in Sydney on October 29, 2019. Sculpture by the Sea is the world's largest annual, free-to-the-public, outdoor sculpture exhibition. (Photo by Peter Parks/AFP Photo)

A chimpanzee in the Osnabrück Zoo in Lower Saxony makes contact with a small zoo visitor sitting in front of a pane on September 1, 2020. The two males Lobo and Lome moved from Leipzig Zoo to Osnabrück Zoo to strengthen the social structure of the existing group. (Photo by Friso Gentsch/dpa)

A cat sits on the empty Great Wall on February 23, 2021 in Beijing, China. Affected by the new coronavirus (COVID-19), the number of visitors to Mutianyu Great Wall in 2020 dropped by about 60%. (Photo by Lintao Zhang/Getty Images)