We have a 4 hour layover in Frankfort. Does anyone have an idea on how to best spend the time? Anything to see in the near area?

Not sure if this possibility is the best way to spend the time--but you'll have quite a bit less than 4 hours considering getting transportation after arriving, and then having to get back to the airport soon enough to clear security.

However, in the town of Walldorf on the southern edge of the airport there's a modest but moving holocaust memorial woods dedicated to hundreds of Hungarian Jewish women who worked as forced labor on the airport runways at the end of WWII. They were helping to strengthen the runways for the jet aircraft Germany employed the last few months of the war. It's a circular path through the woods with memorial placards along the way telling their story.

It's a pleasant walk on its own, but I think the placards are only in German (my memory is not what it was a few years ago), so it would make it more interesting if you had some high school or college German floating around in your brain somewhere.

If you're interested, I'll pull out my notes on the trip and give directions--it would be a quick taxi ride from the airport (10-15 minutes maybe). I do remember a couple of street names--Nordendstrasse and Farmstrasse, but my notes are more detailed. It's not hard to find.

That's about the only thing possible to do. The airport is huge and by the time you disembark and then have to get back to the gate, it leave you very little time.

What about duty free shopping!?

Hi
If you are flying Delta Airlines, do you duty free before you go to there terminal. Last year I thought I could stop off before we got to the ditting area. It is a very long walk behind barricades with no places to shop. Do your shopping before you go to the gate.