A couple covered in mud wait for it to dry at the Salt-works lakes near the Black Sea town of Burgas in Bulgaria on July 25, 2019. Thousands of tourists visit the red salt lakes for mud baths, which are believed to help the healing of muscular disorders and rheumatism. (Photo by Nikolay Doychinov/AFP Photo)

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)

A toddler dressed as Hindu Lord Krishna takes part in Krishna Janmashtami celebrations at a temple in Kolkata, India, on August 23, 2019. Krishna Janmashtami is an annual Hindu festival that celebrates the birth of Lord Krishna, the eighth avatar of Vishnu. (Photo by Tumpa Mondal/Xinhua News Agency)

Pittsburgh police officers stand near a Port Authority bus that had fallen into a sinkhole along 10th Street and Penn Avenue in Pittsburgh on Monday, October 28, 2019. The bus and a car fell in the sinkhole shortly before 8 a.m. One person was taken to the hospital for a minor injury. (Photo by Kristina Serafini/Pittsburgh Tribune-Review via AP Photo)

LiLou the therapy pig stands in front of a departures board at San Francisco International Airport in San Francisco, California, U.S. October 4, 2019. (Photo by Jane Ross/Reuters)

A military enthusiast dressed as World War Two Red Army officer sits in a cafe as he marks the 75th anniversary of the Nazi Germany invasion, in Brest, Belarus June 21, 2016. (Photo by Vasily Fedosenko/Reuters)

Thousands of travellers heading to their hometowns to celebrate Eid al-Fitr, the Muslim holiday to mark the end of Ramadan, wait in a traffic jam to board a ferry at the entrance to Gilimanuk port on Bali, Indonesia July 3, 2016 in this photo taken by Antara Foto. (Photo by Nyoman Budhiana/Reuters/Antara Foto)

A baby dives as his mother holds on tightly during a water baby class in Odessa, Ukraine on August 6, 2016. (Photo by Andrey Nekrasov/Barcroft Images)