Nyhavn

Every postcard of Copenhagen features this canal, and for good reason — but Nyhavn's candy-coloured facade hides a past that would make a sailor blush. King Christian V had the canal dug between 1671 and 1673, using Swedish prisoners of war from the Dano-Swedish conflict as labour. The original purpose was entirely commercial: a gateway from the sea to the King's New Square, where merchants could unload cargo directly into the heart of the city. For the next two centuries, Nyhavn was not a tourist attraction. It was a rough, rowdy waterfront strip packed with alehouses, brothels, tattoo parlours, and the kind of establishments where a knife fight was considered light entertainment.

Hans Christian Andersen lived at three different addresses along this canal — No. 20, No. 67, and No. 18 — spanning thirty years of his life. He wrote his first fairy tales at No. 20 in 1835, including The Tinderbox and The Princess and the Pea. The man who invented some of the most beloved children's stories in history did so overlooking a street famous for prostitution and public drunkenness. That irony seems to have been lost on nobody, least of all Andersen himself.

The oldest surviving house is No. 9, dating from 1681, just eight years after the canal was completed. The colourful painted facades that define the street today were not always so cheerful — the tradition of painting harbour buildings in bright colours was practical, helping inebriated sailors identify which house they needed to stumble back to after dark. The sunny northern side became the fashionable address, while the shadier south side remained grittier for longer.

Today Nyhavn is Copenhagen's most photographed spot, lined with restaurants where you can sit with a beer and watch the old wooden ships moored along the canal. The transformation from den of iniquity to Instagram backdrop took roughly a century, but the buildings haven't changed. Only the clientele has.