As the Japanese summer reaches its sweltering zenith, a steamy cup of coffee in the morning no longer seems quite so inviting. It's time to drop your inhibitions, and reach for some ice.

Contrary to popular belief, iced coffee wasn't invented in Japan — it originated in 1840s Algeria, where French soldiers developed a fondness for a mixture of coffee syrup and cold water known as mazagran.

But Japan was certainly an early adopter: Fashionable cafes started serving iced coffee here in the 1920s, and the drink became widespread during the postwar years.