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)

Audrey Hepburn cooking at home, 1954. Colorized by Dana Keller.

Mates Jimi Hunt and Dan Drupstee dug the 650m slippery slide on a property at Helensville, northwest of Auckland and opened it this weekend as part of a festival to help combat depression.

Three young women preparing a guy. They are sitting him on a keg labelled “gun powder”. (Photo by Fox Photos/Getty Images). 1929

A tiger cub has a short chat with a chimp. (Photo by Ian Tyas/Keystone Features/Getty Images). 27th November 1979

A Leyland lorry during the railway strike, “we supply both milk and baby” is chalked on the bonnet. (Photo by A. R. Coster/Topical Press Agency/Getty Images). 3rd October 1919

Photographer Han Youngsoo captured the ordinary people of Korea as the country emerged from war into an age of prosperity. Han Youngsoo: Photographs of Seoul 1956–63 is at the International Center of Photography (ICP), Jersey City, New Jersey, until June 9, 2017. Here: Seoul, Korea. (Photo by Han Youngsoo/The Guardian)

Yakutsk, with a population of around 270,000, holds its own title: that of the coldest city on Earth. Here: Frost-encrusted house in the city centre. (Photo by Amos Chapple/Courtesy Images/RFE/RL)