Musicians of the alphorn band "Holdersberger Alp- Traum- Blaeser" perform their skills on a raft floating on the Elbsee lake near Aitrang, southern Germany, on June 11, 2017. (Photo by Karl-Josef Hildenbrand/AFP Photo/DPA)

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)

Strokkur geyser against cloudy sky at sunset. Strokkur is a fountain geyser located in a geothermal area beside the Hvítá River in Iceland in the southwest part of the country, east of Reykjavík. It is one of Iceland's most famous geysers, erupting once every 6–10 minutes. Its usual height is 15–20 m, although it can sometimes erupt up to 40 m high. (Photo by Teatsche Dijkhuis/Getty Images/EyeEm)

Teens got their glad rags on as they hit the town in Newcastle city centre, United Kingdom on August 16, 2018, as they celebrate their exam results. (Photo by North News and Pictures/NNP)

A stroller walks his dogs in an autumnally colored forest in Cuxhaven, nothern Germany on November 7, 2018. (Photo by Patrik Stollarz/AFP Photo)

In this Wednesday, April 3, 2019, photo, children play in the water on a beach as a mosque collapsed during the Sept. 28, 2018, earthquake is seen in the background in Palu, Central Sulawesi, Indonesia. The earthquake spawned a large localized tsunami that wiped out coastal areas, while liquefaction caused by the shaking turned entire neighborhoods into rivers of sludge. The disaster killed thousands of people, making it the world’s deadliest seismic event in 2018. (Photo by Tatan Syuflana/AP Photo)

A girl in an angel costume walks with her family past vegetable vendors in Havana, Cuba, Wednesday, April 10, 2019. (Photo by Ramon Espinosa/AP Photo)

Filipino children frolic next to ships taking shelter inside a seaport in Navotas city, north of Manila, Philippines, 27 August 2019. According to the latest advisory from Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA), Tropical Storm Podul intensified from a tropical depression into a tropical storm on August 27, while moving toward Central Luzon with a maximum winds of 65 kilometers per hour and gustiness of up to 80 km/h. (Photo by Francis R. Malasig/EPA/EFE)