Long winter weekend - where?

[Maltester71]

It’s my fiftieth birthday around December and I’d really like a European city break.

In particular, somewhere that’s not too far from an airport (don’t mind quick train ride) but that might feel very Christmassy snd might have mountains!

i have already been to Berlin, Munich, prague, Nice, Barcelona, Paris, Athens, Amsterdam.

i think I want to go to Switzerland, but need help deciding where!