Flickr users make accidental maps

Billions of photos have now been uploaded to the internet, and many are tagged with text descriptions. Some are even geotagged – stamped with the latitude and longitude coordinates at which the image was taken. David Crandall and colleagues at Cornell University in Ithaca, New York, analysed the data attached to 35 million photographs uploaded to the Flickr website to create accurate global and city maps and identify popular snapping sites.See a gallery of the Flickr mapsThe enormous dataset provides a global picture of "what the world is paying attention to", the researchers say. They ran statistical analyses to identify the more important clusters on each map. Next they analysed the text tags added to photographs in those clusters, as well as key visual features from each image, to automatically find the world's most interesting tourist sites.According to Flickr, New York is the world's most photographed city. But London contains four of the seven most photographed landmarks in the world – Trafalgar Square, the Tate Modern art gallery, Big Ben and the London Eye. Some bizarre results emerged – the Apple Store in Manhattan is the fifth-most photographed place in the city.