Londoners walking through Potters Field Park were surprised to see a “money tree” blooming with £9820 in £10 notes, the average amount a working British family has in savings, on July 24, 2014 in London, England. The tree was planted by Sunlife to encourage the nation to start saving at least £10 a month for a brighter future. (Photo by Tristan Fewings/Getty Images for SunLife)

In this photograph taken on October 27, 2017 an Afghan woman collects saffron flowers after picking them in a field on the outskirt of Herat For years, Afghanistan has tried to give farmers alternatives such as fruit crops and saffron to wean them away from poppy farming – the lifeblood of the Taliban insurgency. International donors have splurged billions of dollars on counter- narcotics efforts in Afghanistan over the past decade, including efforts to encourage farmers to switch to other cash crops such as saffron. But those efforts have shown little results. (Photo by Hoshang Hashimi/AFP Photo)

The CBRE Urban Photographer of the Year competition – now in its ninth year – encourages professional and amateur photographers to capture cities at work. Here: Dog Walker – 15:00. The competition allows photographers to enter up to 24 images, one representing each hour of the day. (Photo by Johanna Siegmann)

Runners warm up during the Team Pants And Bra photcall at City Hall on January 26, 2012 in London, England. Team Pants and Bra sprinted through central London this morning, encouraging fellow runners to join TeamPB and proudly wear pants and bras for the Virgin London Marathon in April, representing The Prostate Cancer Charity and Breast Cancer Care. (Photo by Ian Gavan/Getty Images for Prostate Cancer)

In this combination image visitors to the London Super Comic Convention dress as their favourite Marvel comic characters at ExCel on February 25, 2012 in London, England. Visitors to the Comic Convention are encouraged to wear a costume of their favourite character. (Photo by Peter Macdiarmid/Getty Images)

An adult helps a young girl light a cigarette as a band plays in the background in the village of Vale de Salgueiro, northern Portugal, during the local Kings' Feast Friday, January 5, 2018. The village's Epiphany celebrations, called Kings' Feast, feature a tradition that each year causes an outcry among outsiders: parents encourage their children, some as young as 5, to smoke cigarettes. (Photo by Armando Franca/AP Photo)

Guests spend the night in the beach bar so called club of the visionairs in the early morning hours of August 21, 2011 in Berlin, Germany. Berlin, which is among Europe's most popular travel destinations, is crisscrossed with canals and rivers over which lead a total of 564 bridges. The city's ample access to water has encouraged many bar and restaurant owners to create beach atmosphere as a growing summer day- and nightlife institution. (Photo by Carsten Koall/Getty Images)

An actress dressed as Black Cat poses for a photo at the London Super Comic Convention at the ExCeL Centre on February 23, 2013 in London, England. Enthusiasts at the Comic Convention are encouraged to wear a costume of their favourite comic character and flock to the ExCeL to gather all the latest news in the world of comics, manga, anime, film, cosplay, games and cult fiction. (Photo by Jordan Mansfield)