Frankfurt has nothing much.
After spending one day there, take a little trip to Hidelberg,
where you have a big nice castle to tour about :)
Or Köln for the very nice twin peaked Kölner Dom.
It's not very far away...
My suggestion... If you are going to stay in Frankfurt for a
while, use your Eurail pass to take quick ICE to either hidelberg
or köln (cologne), then back...
Moi finalised routing now is~...
10th Sept -> Paris arrival in the morning. Full day tour,
nite in Paris.
11th Sept -> Morning and afternoon tour, include Lourve.
Overnite in train.
12th Sept -> Full day tour of Berlin. Overnite in Berlin.
13th Sept -> Morning departure to Dresden. Afternoon city tour
and overnite.
14th Sept -> Morning departure to Munich. Afternoon tour.
Overnite in Munich.
15th Sept -> Morning train to Fussen(Neuschwanstein Castle).
Nite in Munich.
16th Sept -> Morning train to Vienna. Evening tour of Vienna.
Nite in Vienna.
17th Sept -> Full day tour of Vienna. Nite in Vienna.
18th Sept -> Morning train to Salzburg. Full day city tour. Nite
in Salzburg.
19th Sept -> Morning train to Zurich. Transit train to Basel.
Nite in Basel.
20th Sept -> Full day tour of Basel. Nite in Basel.
21st Sept -> Noon train to Luzern. Afternoon tour to Luzern.
Nite in Luzern.
22nd Sept -> Morning train to Zurich, 4 hours there. Noon train
to Frankfurt for nite.
23rd Sept -> Full day tour of Frankfurt. Nite in
Frankfurt.
24th Sept -> Noon train to Cologne. Evening tour. Nite in
Cologne.
25th Sept -> Morning and afternoon tour. 4p.m train to Frankfurt
Flughafen.