Sheep walk as they are herded to summer pastures in Serra da Estrela, near Seia, Portugal June 27, 2015. In late June, shepherds young and old in the Seia region of central Portugal start guiding sheep, goats and cattle to the Serra da Estrela, the country’s highest mountains, in search of better pastures. There they stay until the end of September. Modern-day shepherds may have mobile phones to keep in touch with family and friends, but their lifestyle has changed little for centuries. The sound of cowbells and the bark of longhaired mastiffs starts early in the morning as the animals – often decorated with traditional woollen balls on their horns – are herded up steep, narrow paths. (Photo by Rafael Marchante/Reuters)

A Naga sadhu, or naked Hindu holy man, pauses inside a tent during Kumbh Mela, or Pitcher festival, at Trimbakeshwar, India, Thursday, August 27, 2015. Hindus believe taking a dip in the waters of a holy river during the festival will cleanse them of their sins. The festival is held four times every 12 years. (Photo by Bernat Armangue/AP Photo)

A little boy shouts “Earthquake!” during a shouting contest, part of the annual evacuation drill on the National Disaster Prevention Day on September 1, 1986. The contest was aimed at teaching youngsters the importance of telling neighbors quickly and loudly of a disaster when it hits. The drill is annually conducted through out the country on the day marking the anniversary of the Great Kanto Earthquake that hit the Japanese capital and its vicinity on September 1, 1923, killing more than 104,000 people. (Photo by Sadayuki Mikami/AP Photo)

Clowns and entertainers gather to attend an annual service of remembrance in honour of British clown Joseph Grimaldi at All Saints Church in Haggerston in London, Britain, February 5, 2017. (Photo by Toby Melville/Reuters)

A detailed view of the BMW 1600 during the The 40th Antwerp Classic Salon run by SIHA Salons Automobiles and held at Antwerp EXPO Halls on March 3, 2017 in Antwerpen, Belgium. (Photo by Dean Mouhtaropoulos/Getty Images)

Woman on swings attached to a float during the Sexual Freedom Parade, part of Naughty in N'awlins held in New Orleans, Louisiana, Wednesday July 5th, 2017. These are the photos from inside the world’s largest swinging convention for couples. The exclusive images reveal the unlikely couples who like to engage in sexual relations with other people besides their partners – and show that swinging is more ‘normal’ than you think. (Photo by Mathew Growcoot/News Dog Media)

In this Friday, September 15, 2017 photo, ballet dancers from Uruguay’s National ballet of the Sodre put on lipstick before a dress rehearsal for Romeo and Juliet in Montevideo, Uruguay. Dancers practice Monday through Friday for eight hours at a time. (Photo by Matilde Campodonico/AP Photo)

Chinese model Ming Xi falls down on runway during the 2017 Victoria's Secret Fashion Show at Mercedes-Benz Arena on November 20, 2017 in Shanghai, China. (Photo by VCG/VCG via Getty Images)