A mahout bathes his elephant in the river Sabarmati on a hot summer day in Ahmedabad, India May 21, 2017. (Photo by Amit Dave/Reuters)

Roof-topping enthusiast Daniel Lau takes a selfie with high-rise buildings down below as he stands on the top of a skyscraper in Hong Kong, China on August 15, 2017. A craze that began in Russia has now taken hold in Hong Kong, one of the world's most vertical cities. Mr Lau said he had been inspired by Russian climbers and that he was unafraid of the vertiginous heights he scales. (Photo by ImagineChina/Rex Features/Shutterstock)

Cave Diver, Anhumas Abyss, Bonito, Brazil: The Anhumas Abyss is an underground cavern with a crystal-clear lake below, more than 260 feet (79 m) deep. A visitor must enter through a narrow opening at the top of the chamber and rappel into the cave. Snorkeling and scuba diving in the lake reveal amazing scenery. Distinctive, conical limestone stalagmites and stalactites occupy the lake and the surrounding area, some reaching 65 feet (20 m) high. (Photo by Marcio Cabral/Nature’s Best Photography Awards 2017)

Lush green rice terraces sprawl over 2,200 hectares of mountainside ready to be harvested. These stunning images, captured by photographer Saravut Whanset, show the incredible terraces throughout the course of the day, including at sunrise and sunset. Workers tend to the fields, with each terrace between 1 and 1.5 metres wide, while wooden huts stand on stilts on the mountainside. The beautiful panoramic pictures were taken in Mu Cang Chai, Vietnam, with the fields located at the foot of the Hoang Lien Son mountain range, 1,000 metres above sea level. (Photo by Saravut Whanset/Solent News and Photo Agency)

A SpaceX Falcon Heavy rocket lifts off from historic launch pad 39-A at the Kennedy Space Center in Cape Canaveral, Florida, February 6, 2018. The world' s most powerful rocket, SpaceX' s Falcon Heavy, blasted off Tuesday on its highly anticipated maiden test flight, carrying CEO Elon Musk' s cherry red Tesla roadster to an orbit near Mars. Screams and cheers erupted at Cape Canaveral, Florida as the massive rocket fired its 27 engines and rumbled into the blue sky over the same NASA launchpad that served as a base for the US missions to Moon four decades ago. (Photo by Thom Baur/Reuters)

An ethnic Lisu man dances barefoot on hot charcoal embers to celebrate the annual Knife Pole Festival in Luzhang township of Nujiang Lisu Autonomous Prefecture in Yunnan province, China, March 29, 2018. (Photo by Aly Song/Reuters)

These friends took a tumble after sharing a hug in Leeds in northern England on May 17, 2021, as Covid-19 lockdown restrictions ease. (Photo by London News Pictures)

A young Iranian woman walks in Tehran on June 14, 2021, ahead of the June 18 presidential elections. Iran is gearing up for a presidential election on June 18 but many young people are more focussed on the daily struggle to survive and their dreams for the future. Jobs are scarce in a recession-hit economy battered by sanctions, a crisis exacerbated by the region's worst outbreak of the Covid pandemic. (Photo by Atta Kenare/AFP Photo)