A five-year project to reveal "the most interesting places in the world" has surprised its creator, revealing pockets of photographic fascination he didn't know existed.

A map showing clusters of photos taken in London and the pathways of the photographers. Credit:The Geotaggers' World Atlas

There are more than two billion geotagged photos on Flickr. A "cluster" of geotagged photos showed a location was interesting because people had gone there, and then taken the extra effort to post their photos online, Mr Fischer said.

"And a sequence of photos along a route is even more significant, because it indicates that someone sustained their interest over distance and time rather than taking one picture and turning back." he wrote in a blog post.