Hello,
how much time do you have for the tour?
Because, if there are enough days, I'd suggest to visit some main capitals, moving from one to another by train. In this way you could experience the land more completely.
For example, starting from London:
London > Paris > Amsterdam > Copenhagen > Berlin > Prague > Vienna > Rome > Madrid
(I'm not 100% sure actually, but I think each of those ways from a town to the next should have a direct train to use... )
