People enjoying the races on a wet day at Chester Racecourse on May 12, 2017 in Chester, England. (Photo by Alan Crowhurst/Getty Images)

Colorado Gov. John Hickenlooper shows off his socks--one with Democratic presidential candidate Bernie Sanders and the other with Republican candidate Donald Trump – before entering his former brewpub for a book signing event to mark the release of his autobiography Thursday, May 26, 2016, in Denver. Hickenlooper, who is term-limited, is doing book talk rounds this week, reviving speculation that he is positioning himself to join Hillary Clinton's presidential campaign ticket. (Photo by David Zalubowski/AP Photo)

This photo provided by Netflix/naturepl.com and WWF-International shows an African Elephant (Loxodonta africana) in front of double rainbow, in Masai Mara, Kenya, included in the Netflix natural history series, “Our Planet”, in collaboration with Silverback Films and WWF. The eight-part series debuts in 2019. (Photo by Andy Rouse/Naturepl/WWF-International/Netflix via AP Photo)

Hannah Rice, 18, jumps from a stump after posing for a photograph next to a large bust of President Franklin D. Roosevelt while touring busts of U.S. presidents in Williamsburg, Va. on March 30, 2019. The statues were once part of an attraction called Presidents Park, which has since closed. (Photo by Matt McClain/The Washington Post)

United States' defender Crystal Dunn (R) vies for the ball with Sweden's forward Sofia Jakobsson during the France 2019 Women's World Cup Group F football match between Sweden and USA, on June 20, 2019, at the Oceane Stadium in Le Havre, northwestern France. (Photo by Bernadett Szabo/Reuters)

Marchers kiss as they walk down 5th Avenue as they part in the 2019 World Pride NYC and Stonewall 50th LGBTQ Pride Parade in New York, U.S., June 30, 2019. (Photo by Lucas Jackson/Reuters)

Tourist Amy Powers is approached by “Walker” Matthew Tomlin during The Walking Dead Tour of a Season 3 location of the AMC production in Haralson, Georgia, U.S. on June 15, 2019. (Photo by Chris Aluka Berry/Reuters)

At 10,582 square kilometres, the Bolivian salt flats – otherwise known as Salar de Uyuni – are the largest on the planet and contain between 50 and 70% of the world’s lithium reserves. After exploring Chile and Argentina, photographer Joel Santos decided to travel to Bolivia in January 2017 to check the salt flats off his bucket list. With an electrical storm rolling in, Joel and his two travelling companions were the only souls left on the vast flats and captured the eerie flats without a person in sight. (Photo by Joel Santos/Barcroft Images)