It does look like a CD to me. With a definite shadow. Hard to tell if it's something physically at that location, or sitting on the image when it was photographed. (Like the packing tape and post-it note picks.) One problem with the "On image" possibility is how far the shadow is from the "CD". It must be a bit above the image to generate a shadow like that, not sitting right on it.
yes, it's strange, because the shadow is far away the "CD", at this scale, the flying "CD" is aprox. 50 or 100 m from ground... It is to highr for beeing a building or so...
flying "CD" or flying "Saucer" ?
After a few hours of web search, here is another picture, older than this one... and... the flying CD is here too, at the right bottom.
It's definitively a water tower ;-)
Towers - Water Storage 
flying "CD" or flying "Saucer" ?
http://maps.google.com/maps?ll=59.252969,18.064442&spn=0.007614,0.009917&t=k&hl=en
Thought this one doesn't cast the same neat shadow.
http://maps.google.com/maps?ll=59.455916,18.069366&spn=0.007614,0.009917&t=k&hl=en
After a few hours of web search, here is another picture, older than this one... and... the flying CD is here too, at the right bottom.
It's definitively a water tower ;-)
http://asso.ffv.fr/cvsq/Historique/Histoire%20d'eau_fichiers/image011.jpg