Syrian refugee and Olympic swimmer Yusra Mardini is pictured during a training session in a pool at the Olympic park in Berlin, Germany on April 26, 2018. (Photo by Fabrizio Bensch/Reuters)

A man rides a horse while others swim on the beach of Gaza City, Friday, August 3, 2018. (Photo by Khalil Hamra/AP Photo)

A sandstorm hits the city of Zhangye in Gansu province, China on November 27, 2018. (Photo by Reuters/China Stringer Network)

A man gets stuck under debris at a damaged site after an airstrike in the Saqba area, in the eastern Damascus suburb of Ghouta, Syria, January 9, 2018. (Photo by Bassam Khabieh/Reuters)

The music group, Boyfriend, performs at the Gentilly Stage at the New Orleans Jazz & Heritage Festival in New Orleans, Thursday, April 25, 2019. (Photo by Doug Parker/AP Photo}

People take pictures of the Tribute in Light while it is illuminated next to the Statue of Liberty (C), One World Trade Center and the Empire State Building during events marking the 14th anniversary of the 9/11 attacks on the World Trade Center in New York September 11, 2015. (Photo by Eduardo Munoz/Reuters)

Visitors watch as Grigory Broverman, a member of the Cryophile winter swimmers club, pours a bucket of cold water over his 6-year-old daughter Liza during a flash mob, part of a celebration of Polar Bear Day at the Royev Ruchey Zoo in a suburb of the Siberian city of Krasnoyarsk, Russia, November 29, 2015. The air temperature was around minus 5 degrees Celsius. (Photo by Ilya Naymushin/Reuters)

Baldwin Street, in Dunedin, New Zealand, is considered the world's steepest residential street. It is located in the residential suburb of North East Valley, 3.5 kilometres (2.2 mi) northeast of Dunedin's city centre.