A man arranges a display of cacti during preparations for the RHS Chelsea Flower Show in London, Britain May 21, 2016. (Photo by Neil Hall/Reuters)

Shaolin monks pose for a photograph in Chinatown on February 23, 2015 in London, England. The monks practice Shaolin Kung Fu which is believed to be the oldest institutionalised style of kung fu and are demonstrating their skills while in the UK. (Photo by Carl Court/Getty Images)

A man dressed as Ironman takes a seat in the cafeteria on the second day of the London Super Comic Convention at the ExCel centre in east London, on March 15, 2015. (Photo by Justin Tallis/AFP Photo)

People hold out money as butchers sell their remaining produce of the year at discounted prices during the traditional Christmas Eve auction at Smithfield's market in London December 24, 2015. (Photo by Neil Hall/Reuters)

A man sits waiting for a train on the London Underground in 1890, when the platform floors were still made from wooden floorboards. (Photo by Hi-Story/Alamy Stock Photo)

Clowns and entertainers gather to attend an annual service of remembrance in honour of British clown Joseph Grimaldi at All Saints Church in Haggerston in London, Britain, February 5, 2017. (Photo by Toby Melville/Reuters)

A woman lies injured after an incident on Westminster Bridge in London on Wednesday, March 22, 2017. A police officer has been stabbed near to the British Parliament and the alleged assailant shot by armed police. Scotland Yard report they have been called to an incident on Westminster Bridge where several people have been injured by a car. (Photo by Toby Melville/Reuters)

A participant peeks from his costume before the start of the the annual London Pantomime Horse Race in Greenwich, Britain December 13, 2015. (Photo by Neil Hall/Reuters)