It’s enough to make your head spin. The photographer Katherine Young set out to shoot spiral staircases in London, England to great effect, including this shot she calls the Downward Spiral Part III. (Photo by Katherine Young/Rex Features/Shutterstock)

A man performs a split as he practices Kung Fu at Beihai Park in Beijing, China August 20, 2017. (Photo by Reuters/China Stringer Network)

Cropped shot of a woman flirtatiously touching leg of man in a suit with her foot under the table. (Photo by LightField Studios/Skyfish Digital Media/Getty Images)

A resident looks at a parade marking the 496th anniversary of Panama City, Panama August 15, 2015. Modern-day Panama City includes the historical ruins of the original Panama Viejo settlement founded on August 15, 1519 by Spaniard Pedro Arias Davila, according to local media. (Photo by Carlos Jasso/Reuters)

Carlos Bahia, dressed as Santa Claus, talks with boys at the Maresias beach, in the state of Sao Paulo December 9, 2014. In the Southern Hemisphere summer starts on December 1, so while countries in the north are experiencing a white Christmas with grey skies, those in the south are busy surfing and sunbathing in temperatures just shy of 100 degrees Fahrenheit (38 degrees Celsius). (Photo by Nacho Doce/Reuters)

An Afghan refugee girl stands near her parents' makeshift shelter in a slum on the outskirts of Lahore January 12, 2015. (Photo by Zohra Bensemra/Reuters)

Competitors line up their boats for some formalities during the Aberdeen Dragon Boat Races. (Photo by Jessica Hromas)

In this Wednesday, August 20, 2014 photo released by Red Bull, Maikel Melero of Spain warms up prior to the fifth stage of the Red Bull X-Fighters World Tour in the South African savanna of Pretoria, South Africa. (Photo by Joerg Mitter/AP Photo/Red Bull)