Day Trip from Frankfurt - Burg Eltz, Rothenburg, or Cologne?

Burg Eltz closes on Nov. 1 for the winter, so you can scratch that one. Cologne is not a charming city. It was heavily bombed in the war and very little old world charm remains. It was re-built modern. The only time I would recommend visiting is during their fabulous Christmas markets. That leaves Rothenburg, which is an adorable town and well worth a visit. It is easiest to rent a car.

Rothenburg is way too far for an easy day trip by train. 5-6 hours round trip. No castle either. It's nearly 4 hours round trip by car, but then you have the added pick-up drop off time and other assorted hassles.

I suggest you take the direct train to Rüdesheim on the Rhine River (70 minutes) where you can walk some cobblestones, see the town on foot, try the local wine, have a meal:

https://i.pinimg.com/originals/da/78/1b/da781ba904b2a87a580cc9415420dc79.jpg

https://www.tripadvisor.com/Attraction_Review-g187345-d546947-Reviews-Siegfried_s_Mechanisches_Musikkabinett-Ruedesheim_am_Rhein_Hesse.html

The Rhine Valley is Germany's most scenic train ride. Trains run along both river banks and offer great views on the way. Think castles, old-world towns, jagged cliffsides...

https://i2.wp.com/herbert-piel.de/wp-44b92-content/uploads/2016/01/Loreleytal.jpg?fit=960%2C641

It pales a bit in winter, but the towns are still there - and 50 train minutes northof Rüdesheim on the same train line is the attractive old-world town of Braubach.

https://delveintoeurope.com/braubach-germany/

MARKSBURG CASTLE is a medieval castle that sits high on the cliffs above the town and the river; it is open year-round and is accessible on foot in 25 minutes from town - or you may wish to order up a taxi.

https://img.fotocommunity.com/marksburg-braubach-bc203e81-d606-4f2f-bb8d-17e275e8ba88.jpg?height=1080

https://www.marksburg.de/en/circuit/#/

After your tour, board a direct train straight back to Frankfurt on the same railway you used to get here.

You may wish to see Braubach first, then Rüdesheim later. There are more dining options in Rüdesheim than Braubach.

A single train ticket will cover the round-trip from Frankfurt... the Day ticket for Germany costs €63/2.

https://int.bahn.de/en/offers/regional/day-ticket-germany

My gut feeling would be that Rothenburg is too far as well, and indeed Cologne was flattened 98% or so in the war.
Two ideas easily doable from Frankfurt by train would be Idstein (small but charming) and particularly Limburg (larger, still loads of timberframe, large and old cathedral).

Everything you want to see is open on Sundays. Only stores are closed on Sundays. Museums, tourist attractions, restaurants, etc. are all open on Sundays.
Check out Büdingen (which is similar to Rothenburg, but in my opinion a lot better), Limburg, Marburg, Eltville & Eberbach Monastery. These places are all within 1 hour by train from Frankfurt.

Rick doesn't like Heidelberg very much, but I thought it made a very nice daytrip from Frankfurt by train. Nice castle and an interesting town.

As noted Burg Eltz will be closed in November, and Cochem is pretty much shut down. RodT is to far away for a day trip, and I feel the same about Cologne. I'd go to either Mainz, Wiesbaden, or Bad Homburg. Mainz has the Chagall Windows, the Isis Temple and Amphitheater, and the Gutenberg Museum as well as the (rebuilt) old town. Wiesbaden has the old town and is just a pretty place to walk around. Bad Homburg has a castle, the royal spa, and the gardens (which will not be a huge attraction in Nov. )

Heidelberg is always a good way to spend a day too. I'm usually there at least one day in Nov. doing my Christmas shopping. And just an hour away, towards RodT, is Wurzburg, which, if you haven't been there, is really worth visiting for the Residence and fortress.

Sundays are usually quiet, but while most of the small shops and supermarkets are closes, restaurants and museums are usually open after 10 am. Mondays are the day museums are usually closed.

All of the places I've mentioned are very easy to get to by train, and easy to walk from the train stations.

Have you been to Wurzburg? If not, I think it's worth considering as a day trip from Frankfurt via train. In addition to the main sights, it's a pleasant and walkable small city. Worth considering. Good luck with your travel planning!

Agree that Rothenburg is too far for a day trip by any means. If you are looking for a quaint, old timbered town, Miltenberg is a lot closer.

As mentioned, Wurzburg is only an hour or so by train and one can easily spend a day there. The Residence (especially the chapel) is not to be missed if you go there.

Google them and see if they strike your fancy.

rebeckah: While Cochem is somewhat like Rothenburg - and Cologne is somewhat like Düsseldorf - the first two places are drastically different from the last two destinations you have in mind.

As some have pointed out, many of the larger destinations that hve been suggested were WW II bombing targets - rubble, really, before being rebuilt after the war's end; this group, by the way, includes Würzburg. Other towns we've suggested feel much more like the old-world villages that they were hundreds of years ago.

If you want help narrowing down the choices, please let us know what your travel interests and preferences might be.

I understand that Wiesbaden has an art nouveau museum. That's of interest to me.

Mainz is cute and charming and an easy ride from Frankfurt - there is enough to do that would fill a day and get you back to Frankfurt at a decent time.

Personally, I liked Cologne. The cathedral is super impressive. We did a bike tour of the city that we really liked to see both sides of the river.

Janet, if you or OP are into Art Nouveau, probably even more interesting is „Mathildenhohe“, an Art Nouveau quarter in the nearby city of Darmstadt (which is admittedly rather unimpressive otherwise)

Would the Städel be of interest? Have gone here twice this past month and still haven't seen all of it. Monet exhibit is coming soon, so that will be a treat.
https://www.staedelmuseum.de/en/