Two elderly men smoking pipes of opium on a terrace in Korea. (Photo by Bert Hardy/Picture Post/Getty Images). August 1950

Photochromes are vibrant and nuanced prints hand-coloured from black-and-white negatives. Created using a process pioneered in the 1880s, these images offer a fascinating insight into the world when colour photography was still in its infancy. A Tour of the World in Photochromes is at the Swiss Camera Museum, Vevey, until 21 August. Here: Street food in the Strada del Porto in Naples, Italy, 1899. (Photo by Swiss Camera Museum/The Guardian)

A spotless GWR (Great Western Railway) locomotive, the “Royal Sovereign” waiting to carry Queen Victoria's coffin. (Photo by Hulton Archive/Getty Images). 28th January 1901

With temperatures soaring and summer well underway, countless Americans will be spending their Independence Day weekend at the beach. Here we revisit some classic images from the turn-of-the-century to the 1930's of vacations by the sea, from Coney Island to Santa Monica.

Samurai commiting seppuku (hara-kiri) in Japan, circa 1880. (Photo by adoc-photos/Corbis via Getty Images)

Female of pygmy hippopotamus called Malaya from Netherlands in zoo in Dvur Kralove nad Labem, Czech Republic, February 22, 2016. (Photo by David Tanecek/CTK via ZUMA Press)

Two Tibetan women wearing traditional striped aprons, elaborate headdresses and abundant jewellery. Original Publication: From a photograph by Shephard. (Photo by Hulton Archive/Getty Images). Circa 1910

A leg of a “diablito” frog (Oophaga sylvatica) is photographed in a laboratory at a laboratory in the zoo of Cali, Colombia, on July 19, 2019. Colombia is the second country with the largest number of amphibians in the world after Brazil. More than 40% of amphibian species worldwide are in danger of extinction. (Photo by Luis Robayo/AFP Photo)