4 weeks in europe honeymoon.

Hey folks!

My fiancée and I are throwing around ideas for a 4 week Honeymoon in Europe.

It's probably still a fair ways off (long distance, waiting out covid, etc) so we're looking at 2023, possibly September/Octoberish? Shoulder months as to avoid summer heat and tourists (in normal times).

We have stayed in Switzerland before (Zurich, Interlaken, Leukerbad and Luzern) and also have been to Germany (near Frankfurt and down to Neuschwanstein) and probably would aim for something similar.

This means good food, some hiking, old towns, castles, cathedrals, some coasts similar to cinque terre and so on. We definitely want to re-visit Grindelwald, Venice is a maybe, and we're not picky about western or eastern europe as long as it matches the criteria above. We'd be travelling near exclusively by eurorail, I think (car only if absolutely no choice).

On average we'd spend probably 3 nights per main location, 2 if it's less interesting (Paris is probably a place to visit but not stay very long, for example), and we'd probably go mainly airbnb to save on some costs.

Anyone have any similar experiences or suggestions for an itinerary?

Thank you in advance!