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)

South Vietnamese-born designer Quasar drives the six-foot long square-shaped plastic car he built and which is scheduled to be a hit with the young driving set, in Paris, June 23, 1967. The car can be driven at speeds of up to 60 mph (Photo by Michel Laurent/AP Photo)

An adult specimen of Nannospalax (leucodon) montanosyrmiensis, a variant of the lesser mole-rat (Spalax leucodon) is pictured near Albertirsa, some 60 kilometers southeast of Budapest, Hungary, 12 May 2018. The critically endangered rodent lives in several isolated populations in the Carpathian Basin. (Photo by Sandor Ujvari/EPA/EFE)

A Falcon 9 SpaceX rocket, with a payload of 60 satellites for SpaceX's Starlink broadband network, lifts off from Space Launch Complex 40 during a time exposure at the Cape Canaveral Air Force Station in Cape Canaveral, Fla., Thursday, May 23, 2019. (Photo by Malcolm Denemark/Florida Today via AP Photo)

Seljalandsfoss waterfall, located in Iceland. Seljalandsfoss is one of the most famous waterfalls of Iceland. This waterfall of the river Seljalandsá drops 60 metres (200 ft) over the cliffs of the former coastline. It's possible to go behind the waterfall. (Photo by HotSpot Media)