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)

Battersea Power Station. The chimney rims are thinner on top than you might expect. (Photo by Bradley L. Garrett)

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)

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 Burlesque performer onstage during the London Tattoo Convention at the Tobacco Docks, in London, Britain, 24 September 2017. (Photo by Facundo Arrizabalaga/EPA/EFE)

Cosplayers dressed as She- Ra and Emma Frost pose for a photograph at the MCM Comic Con at ExCeL exhibition centre in London on October 28, 2017. (Photo by Tolga Akmen/AFP Photo)

An Aerial view Admiralty Arch at the top of The Mall on July 26, 2011 in London, England. (Photo by Tom Shaw/Getty Images)

The Dynasphere, an electrically-driven wheel, invented by Mr. J. A. Purves of Taunton and his son. It had 2.5 horse power and once attained a speed of 25 mph. (Photo by Fox Photos/Getty Images). 1932