Hilton Garden Inn Frankfurt Airport

The hotel's official website has detailed instructions on how to find it within the airport.

Follow the signs to the long distance train station. The Hilton Garden Inn is located to the right of this train station on an upper level.

Do you arrive at terminal 1 or terminal 2, or are you arriving by train? Why are you staying at the airport when you could be staying in the city and get some sightseeing done and have a nice dinner?
http://www.frankfurt-airport.com/content/frankfurt_airport/en/directions/airport_maps1/terminal_1_2.html

Follow the signs to the long distance train station. The Hilton Garden Inn is located to the right of this train station on an upper level.

Do you arrive at terminal 1 or terminal 2, or are you arriving by train? Why are you staying at the airport when you could be staying in the city and get some sightseeing done and have a nice dinner?

Ms. Jo,

We will be arriving by train from Rothenburg. The main reason we are staying at the hotel is because we will be leaving the very next day and the hotel is right at the airport. We also wanted to take a quick side trip to Cologne after arriving from Rothenburg and I do not want to deal with all kinds of taxis and other hassels.

Does your train arrive at the long distance train station or the regional train station or does it arrive in Frankfurt at the Hauptbahnhof?

Who said anything about taxis or hassles? The trains are super easy and fast. Train every 15 min. and they start running at 04:15 in the morning.

How are you getting to Cologne? Do you have an ICE booked, a train that only takes 55 min.? If so, you will miss the whole Rhine and all of the castles, but the slow trains will take you over 3 hours to get there and 3 hours to get back. This is not a quick trip. You will have spent 3 hours getting here from Rothenburg and then you are going to sit in a train again? If you don't have an ICE booked, this quick trip is going to cost you a lot.

Not trying to dissuade you from your trips, but it doesn't sound very enjoyable.

Nice hotel for the last night -- gets you feeling "Americanized" if you have been in charming B&Bs. ;-)
But the Hilton eating choices seemed uber-expensive for our tastes -- instead, we went to the grocery store in the airport complex and had a simple half-chicken with potatoes for KFC prices. (We had eaten a traditional "green sauce" dinner in Frankfurt the prior night as part of sightseeing.)
Lots of signs pointing to Hilton -- Garden Inn is just next to the regular Hilton -- or helpful airport information staff.

Ms. Jo,

We have not decided on which train to take to Cologne. Possibly ICE because it is faster, but also more expensive. As far as missing things in the Rhine, that is not an issue since we will be spending the first three days of the trip in the Rhine especially to explore the various castles.

Ok. Just as a suggestion, if you are already on the Rhine for those 3 days, why not go ahead and visit Cologne on one of those days instead of needing to back track. Saves you time and money.

The Paulaner in the Squaire which is where the Hilton Garden Inn is located, has pretty good food and it isn't too pricey. Good place for a last evening meal. The Rewe grocery store has a fairly decent variety and there is a new Asian restaurant in terminal 1, by the Meeting Point. Checked the prices there the other day and they were quite low for an airport place. I was surprised. Haven't eaten there yet, but it looks good.

"Nice hotel for the last night -- gets you feeling "Americanized" if you have been in charming B&Bs."

Personally, I'd rather wait another day before having to feel "Americanized".

In 1988, I stayed in Mainz the last night and walked to the Dom. Along the way there were some Burger Kings. I thought a Burger King hamburger would taste good, but then I thought, "Tomorrow I'll be back in the States and can have all the hamburgers I want. This is the last night for a while to have real German food." So I passed on Burger King and ate in a German restaurant.

Interesting suggestion Ms. Jo, though I am not sure we will have time while in the Rhine because we will be using much of the time going to castles and towns. We will be there for about three days and head over to Rothenburg for about two days and then back to Frankfurt for a possible side trip to Cologne on the last day before leaving the day after. Relatively short trip I know, but that is all we could do this time and we are trying to see as much as we can despite the number of trains we may be taking.

If you aren't booked into Rothenburg, you could instead visit one of the other, nearer medieval towns and save yourself time and train fare. It is your outlier. Perhaps consider Büdingen and Gelnhausen. Both are only a short hour long train trip from Frankfurt. A group day ticket from Frankfurt is only 27 €. Büdingen is like Rothenburg, but it is all original (wasn't bombed in WW2 and wasn't burned down in the 30 Years war in the 1600's) It also doesn't have the tour buses and souvenir stores.
Gelnhausen has tons of half-timbered houses and a magnificent church built in 1220.

http://www.buedingen.info/en/
http://www.gelnhausen.de/Sehenswuerdigkeiten.362.0.html