Fun activities at FRA
 

I'm recently considering a long international (non-Schengen to non-Schengen) layover at FRA. Since I've visited Frankfurt city before, I'm not very interested in getting to downtown. I find that there's an observation deck and some very interesting airport tours. But I have no idea if they're at non-Schengen airside. Does anyone know the tour detail or any other interesting things to do?

Did you try looking at the airport website?
It's all pretty clearly laid out!
Also search "FRA airport tour" = http://www.flyertalk.com/forum/germa...port-tour.html

i think they have a casino. go for it. fun fun fun

You could take the train up to Mainz. Pleasant riverside town on the Rhine about thirty minutes north of FRA by S-Bahn. Mainz is Gutenberg's hometown and features a worthwhile museum about his life and work.

I have done the tour. The starting point is landside, and you will go through security again. The tour was interesting, a close look at some tarmac actions (on mine the driver purposefully park a minute near a Condor 767 having its engine checked), a few minutes near the runways. As an avgeek I loved it.
There are some longer options where you can go to the maintenance hangars. The commentaries from the guide are only in german (he was not speaking any english) and there are no english tours.

The casino closed years ago AFAIK.

In addition to Mainz there is Wiesbaden accessible via S-bahn. How long is the long layover. Since high speed trains stop at FRA, there are many possibilities if you can afford 1 or 1.5 hours by train in each direction: Heidelberg, Cologne/Bonn. If you're willing to rent a car, the nearby wine region is lovely.