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 woman with a Japanese style full back body tattoo at the 12th London International Tattoo Convention, which opened today in Tobacco Dock, east London on September 23, 2016. The show features over 400 of the world's finest, most prestigious and elite tattoo artists as well as a showcasing alternative culture in the form of piercing, burlesque and the Miss Pin Up UK competition. Around 20,000 people will attend over the weekend. (Photo by Michael Preston/Alamy Live News)

High-flying photographer Jeffrey Milstein, renowned for his aerial photos of US cities, snaps landmarks through the open door of a helicopter. This month he hired a chopper in London and amazingly he had just an hour to cover all the buildings he wanted to capture including Buckingham Palace, the London Eye, the glass roof of the British Museum and the Gherkin and Walkie Talkie towers in the City. Here: Jeffrey Milstein captured these stunning images through the door of a helicopter hovering over central London. (Photo by Jeffrey Milstein/Rex Features/Shutterstock)

An actor plays an injured passer-by during Exercise Strong Tower, the scene of a mock terror attack at a disused underground station in central London, Britain June 30, 2015. London police held their biggest-ever terrorism drill on Tuesday, pitting the emergency services against a group of marauding attackers, nearly 10 years since four young British Islamists killed 52 people in suicide bombings on London's transport network in July 2005. (Photo by Peter Nicholls/Reuters)

Musician “Girli” poses for a portrait during London Fashion Week in London, Britain February 21, 2017. (Photo by Neil Hall/Reuters)

A man poses as “Lemongrab” from Adventure Time outside the MCM Comic Con at the Excel Centre in East London, October 25, 2014. (Photo by Andrew Winning/Reuters)

A Sumatran Tiger looks at visiting children from it's enclosure during the ZSL London Zoo's annual stocktake of animals on January 5, 2015 in London, England. The zoo's annual stocktake requires keepers to check on the numbers of every one of the 800 different animal species, including every invertebrate, bird, fish, mammal, reptile, and amphibian. (Photo by Dan Kitwood/Getty Images)

The London Eye is a giant Ferris wheel on the South Bank of the River Thames in London. Also known as the Millennium Wheel, its official name was originally the British Airways London Eye, then the Merlin Entertainments London Eye, and since January 2011, the EDF Energy London Eye.