Where do people like to run? You might be surprised by the answer. A digital artist has taken reams of data from the app Runkeeper, and produced these incredible heat maps of popular routes in the world's biggest cities.
The maps are the work of Nathan Yau from Flowing Data, and cover many of the major cities in the US as well as London, Venice, Paris and some other European cities.
The results are interesting although not necessarily that surprising. For some of the cities the heat maps are clearly influenced by local major running events - such as the Venice Marathon - or the path of rivers and parks.
But it's fun and interesting to check out the maps and see if they match up with your own favourite routes.
Yau has also provided code on the site to make your own maps. Check out the code and the full story, as well as more images, at the Flowing Data website.