Those things are everywhere. Did they have time to do anything else. Notice the two windmills in the below picture.
Description Viking stone ship located within the Gettlinge gravefield, southern Öland, Sweden.
http://www.megalithic.co.uk/modules.php?op=modload&name=a312&file=index
Pick a country!
Viking Grave Ship...or a depiction of a planet on an elliptic orbit...hmmm?
http://www.photographersdirect.com/wrpl/stockphoto.asp?imageid=45150&sourceid=95
pre Islam Himyaritic stone circle in Saudi Arabia