The Queen Elizabeth Tower (Big Ben) is reflected in a puddle as a cyclist rides by in London, on 27 June 2016. Britain began preparations to leave the European Union on Monday but said it would not be rushed into a quick exit, as markets plunged in the wake of a seismic referendum despite attempts to calm jitters. (Photo by Leon Neal/AFP Photo)

Festival-goers wash on Shipyard Island, the venue of the 24th Sziget (Island) Festival in Northern Budapest, Hungary, 15 August 2016. The venue, one of the biggest cultural events of Europe, offers art exhibitions, theatrical and circus performances and above all music concerts from 10 to 17 August. (Photo by Szabó Gábor/Origo.hu)

Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

A Bosnian special forces soldier returns fire 06 April 1992 downtown Sarajevo as he and civilians come under fire from Serbian snipers. The Serb extremists were shooting from the roof of a hotel at a peace demonstration of some of 30,000 people as fighting between Bosnian and Serb fighters escalated in the capital of Bosnia- Hercegovina. (Photo by Mike Persson/AFP Photo)

A Shariah law official whips a woman who is convicted of prostitution during a public caning outside a mosque in Banda Aceh, Indonesia, Friday, April 20, 2018. Indonesia's deeply conservative Aceh province on Friday caned several unmarried couples for showing affection in public and two women for prostitution before an enthusiastic audience of hundreds. The canings were possibly the last to be carried out before large crowds in Aceh after the province's governor announced earlier this month that the punishments would be moved indoors. (Photo by Heri Juanda/AP Photo)

Tourists standing near the sea shore are hit by a wave, which surged past a barrier under the influence of Typhoon Chan-hom, in Qingdao, Shandong province, China, July 12, 2015. One of the most powerful typhoons to strike eastern China in decades disrupted air, rail and sea transport on Saturday after forcing the evacuation of more than a million people from the provinces of Zhejiang and Jiangsu, state media reported. (Photo by Reuters/Stringer)

A street cleaner demonstrates his martial arts skills in front of a closed shop near Beijing's Tiananmen Square September 2, 2015 as the capital prepares for tomorrow's parade. (Photo by Damir Sagolj/Reuters)

A woman sells statues of the Ekeko, god of fortune, at the traditional “Alasitas” fair in La Paz January 24, 2015. During the fair, Bolivians buy miniature versions of goods like cars, money and houses they would like to own in real life during the year. (Photo by David Mercado/Reuters)