I was mis-located (new word?) last year at a cafe. Turned out to be a wifi thing. It was strange, but I think my phone grabbed the name or mac address of a nearby wifi router and somehow had that router as being in a completely different place. I was in a college town, so I suppose it's possible a student brought their router with them to school.
Anyway, have you checked location when you're out and about? Have you tried disabling wifi and then checking your location again? Just easy things to try before a restore...
https://discussions.apple.com/thread/3463431
Hope that link works. That thread started a month ago, but the last 8 pages of it are fresh (all posts from the past 48 hours or so). One poster says Apple is now investigating. Some are speculating, since it's Europe that seems to be dominating with this issue, that it may have something to do with Russia's GPS system which I think the newest iPhones / iOS supports. Anyway, seems worth a read...