One of the best option when you traveling Europe is by train, with this kind of transportation, we can freely choose the type of the train we use based on how long the journey, how much time you have for your vacation, and how fast you want to go to your vacation destination.
Things that you must know that if you want to ride European high speed train, you must reserve your seat which the cost can be reduced only if you hold a rail pass. Just for information, a rail pass is the best way to travel around Europe because this pass provide us an unlimited travel within specified validity limits, on the national rail networks of a particular country in Europe, just unlike the other passes.
Next things that you must know is to carefully pick the route to reach your destination, you can choose to directly go there or choose to get on a train from point to point which eventually will ended up in your destination for cheaper price.
But again, all of it must be decided based on how long the journey, how much time you have for your vacation, and how fast you want to go to your vacation destination. Choose carefully and you might have a fun traveling rather than fun vacation.