Originally Posted by
AlanInDC
You don't say when those 10 hours are-- daytime, nighttime
In general, get out of the airport. Take the s-bahn (fast subway train) to Frankfurt city or Mainz, about 30 min trip either way. There are threads on this question in the Germany forum.
Good point. I should arrive FRA around 11 AM, so I have pretty much all day to spend.