Women compare their bikini marks after sunbathing on a terrace to have the perfect bikini line (“marquinha” in Portuguese), at the Erika Bronze spa in Rio de Janeiro, Brazil, November 17, 2016. Women start arriving at the spa between 7am and 8am and will tan for approximately 3 hours. (Photo by Pilar Olivares/Reuters)

A woman dressed in an alien space suit carries an American flag and a sign that reads “Women's Revolution 1971” as she marches in a Women's Liberation demonstration on Fifth Avenue in New York, August 26, 1971. (Photo by Marty Lederhandler/AP Photo)

A picture taken on March 16, 2017 shows women dressed up as mermaids posing by a pool at a mermaid training school in Moscow. Russian women who have dreamt of becoming a mermaid since their youngest years, start turning their fantasies into reality with a new type of fitness – mermaid swimming. (Photo by Natalia Kolesnikova/AFP Photo)

Revellers take part in the traditional “Weiberfastnacht” (Women's Carnival) celebration in Mainz, Germany, February 4, 2016. Germany is celebrating its traditional carnival with tight security after assaults on women during New Year's Eve celebrations across the country. (Photo by Kai Pfaffenbach/Reuters)

2016 Rio Olympics, Athletics, Women's Heptathlon Javelin Throw, Groups, Olympic Stadium, Rio de Janeiro, Brazil on August 13, 2016. Evelis Aguilar (COL) of Colombia competes in Javelin group A women's heptathlon. (Photo by Dylan Martinez/Reuters)

In his series “Ballerinas of Cairo”, photographer Mohamed Taher documents Egyptian dancers making the city streets their stage – pirouetting, leaping and posing their way through their country’s sprawling capital. The photos are, at first glance, stunning snapshots of a city’s vibrant culture in motion. (Photo by Mohamed Taher/Ballerinas of Cairo)

2016 Rio Olympics, Artistic Gymnastics, Preliminary, Women's Qualification, Subdivisions, Rio Olympic Arena, Rio de Janeiro, Brazil on August 7, 2016. Ruby Harrold (GBR) of United Kingdom (341) applies lipstick for Elissa Downie (GBR) of United Kingdom (centre R) during the women's qualifications. (Photo by Damir Sagolj/Reuters)

Women walk through the snow on Wimbledon common with their dogs on February 10, 2012 in London, England. The Met Office cold weather alert remains at Level 3 as southern parts of England continue to suffer from cold weather and freezing conditions, with further snowfall overnight. (Photo by Peter Macdiarmid/Getty Images)