I don't own a smartphone, but I finally searched around the net a bit just now, which led to a a couple of similar qr codes on flickr that pointed to http://www.codepoetry.gr/.

As translated by Google: "The codepoetry poetry is a game in town.
QR codes scattered invite you to discover the poetry hidden in unsuspected corners.
With a smartphone scans the QR code you found him and leads to a 'random poem from the collection is constantly enriched hosted in codepoetry."