I'm planning my first Europe trip (3 week stay) and need help deciding on a 4th city. I will be landing in London October 1st and plan to visit Barcelona and Rome as well. I originally wanted to do Norway or Switzerland as my 4th destination but my travel plans were moved to October so weather/change in greenery has become a factor for both of those countries. I really wanted my 4th destination to be a place with beautiful nature landscapes at least a day trip away.
I am open to recommendations on what's best to go to during the first 2 weeks of October whether it has nature or not. I have researched about Prague, Athens, Amsterdam, Budapest, Dubrovnik, and Paris but I'm not really sold on any of them yet. I'll be flying from city to city as well.
Definitely feeling overwhelmed and would really appreciate any help.
Thank you!