We are going to be in Monte Carlo. We would like to travel from there to Lake Como. Not sure how to handle the travel. Should we take a train? Is there a train? If we travel to Milan, is there a train? After this is done we would like to go to Northern Croatia and visit the big park up north. From there we would like to travel to Budapest. We prefer not to fly. Prefer seeing the country side by train. We have made several trips to Europe so we are not worried about the train etc. Just not sure what our options are. Any help would be great. Thanks.
This may be helpful
www.bahn.com will show you your rail options.
You certainly need to research via sites as recommended above. The Monte Carlo to Varanasi segment via train is doable. It is what we would do, although it take much of a day (almost 7 hours).
Varenna to Zagreb (assume you will need to rent a car?) by train looks to be almost 13 hours. I would break that up and spend a few nights somewhere along the way if you insist on train. Maybe in Venice?
Zagreb to Budapest is about 6 hours by train.
I like the site www.trainline.eu for (some) research and purchasing. They do not cover every train in Europe but they do cover many and it is an easy site to use for purchasing.
The train from Monte Carlo goes to Menton then on to Italy (about 5 more kilometers). I was only going as far as Menton and barely listened to the announcements. Either they were saying the train ended at the next stop or the crew would change out at the next stop. My memory was a crew change but, as I said, I wasn't paying close attention because I was getting off. Either way, it seems you can get to Milan from there.