Andrey Karr from Western Riders Slacklines at sunset above big waves in Nazare, Portugal on December 27, 2017. (Photo by Aidan Williams/National Geographic Travel Photographer of the Year Contest)

Frances Fowler leads the Bowie VFD Marching Thoroughbreds in the Bowie 4th of July Parade in Bowie, Md., on July 4, 1976. (Photo by James M. Thresher/The Washington Post via Getty Images)

A visitor wears an outfit as she watches the St. George NextGen show for Fashion Week in Sydney on May 16, 2017. (Photo by Peter Parks/AFP Photo)

A visitor and autumn foliage are reflected in the lake at Stourhead gardens in Wiltshire, Britain, November 2, 2018. (Photo by Toby Melville/Reuters)

Gymnast Ahmad al-Sawas performs gymnastic moves near damaged buildings in the rebel-held Bustan al-Qasr neighbourhood of Aleppo, Syria March 26, 2016. As Syrian gymnast Ahmad al-Sawas watched his country fall apart, his Olympic dream collapsed too. The last national champion before the fighting began, he knew that supporting the anti-government side in the five-year-old civil war would prevent him from being selected for the Rio Games. (Photo by Abdalrhman Ismail/Reuters)

A hunter holds a shot female pheasant next to his dog “Lola”, a Deutsch female Kurzhaar, during the first day of the Italy hunting season in Castell'Azzara, Tuscany, central Italy, September 20, 2015. The number of hunters in Italy has been decreasing, from 1,701,853 in 1980 to 751.876 in 2007, with a percentage reduction of 55.8%, according to the latest available numbers from the national statistics bureau ISTAT. (Photo by Max Rossi/Reuters)

A Macedonian police officer hits a stranded migrant attempting to cross the Greek-Macedonian border, near Gevgelija, Macedonia December 2, 2015. Picture taken from the Greek side of the border. (Photo by Alexandros Avramidis/Reuters)

Indonesian air force personnel carry the flight data recorder of the ill-fated AirAsia Flight 8501 that crashed in the Java Sea, at airport in Pangkalan Bun, Indonesia, Monday, January 12, 2015. Divers retrieved one black box Monday and located the other from the AirAsia plane that crashed more than two weeks ago, a key development that should help investigators unravel what caused the aircraft to plummet into the Java Sea. (Photo by Achmad Ibrahim/AP Photo)