travel with grandson

Sue, at 20 your grandson is more than old enough to be actively involved in the decision AND the planning. Being taken abroad is a very generous gift indeed and it would seem to me that he should be willing to at least participate in the research that's involved?

Tell him to go to the library, check out some travel guides and make a list of places which interest him. Then sit down together and determine what is realistic for 10 days, and what's possible for two travelers of different generations - any maybe interests - to do together. A 20-year-old may lean to activities which would be challenging for Grandma! :O)

As you're already well traveled, you already have a handle on the time it takes to move from one place to another so you'll be able to keep a rein on the number of those which end up on the list. Personally? I might encourage a couple of locations in a single county so he can experience some of differences. For instance, people whom have never been to Italy may not understand that it's not all the same; that everything from history to architecture to food to customs may be unique to different regions. Make sense?

Based on your experiences in Europe, and understanding what his interests are, do you think he'd prefer a careful selection of more than one place (for a variety of experiences), or would focusing on a single, great city be preferable? If he just wants to go "someplace" with you, it sounds like he'll be open to your suggestions, and maybe you can give him 2 or 3 options and then discuss what destination(s) would be best for the two of you. He's a fortunate kid!

My 14-year-old grandson has already completed three years of Latin study in school (with honors). He's fascinated by ancient Roman history, and also WW2 history. So last May I took him to Rome for four nights; then we took the train over the Alps to Munich for five more.

Before leaving I gave him guidebooks of both cities, along with Rick Steves videos, and together we worked out an itinerary. He was focused and motivated, and we had a great time. Photos here.

When I was 16 years old, I planned our family's entire trip to Europe. We visited 4 countries, rented cars and took trains. This was all before the Internet existed. Put it on him.

I agree with the above. At that age I was travelling in North Africa. Very much alone and with not much more than an obsolete guide on Algeria.
Another point is your itinerary. You've only got 10 days and you're talking about »several countries«. In that time frame, provided the travelling between them doesn't take too long, you can at most visit three destinations. These can be in different countries, but »seeing several countries« is out of the question.

London and Paris (5 days each).
or
Venice (3 nts) >> Florence (3 or 4 nts) >> Rome (3 or 4 nts)

I'd suggest keeping it simple, two stops maximum, and trying to combine someplace you'd like to see, maybe haven't visited before, with someplace a new traveler to Europe is likeliest to enjoy (like London or Paris). That's if he's really leaving it up to you, instead of making his own choices. Of course no one here can know your relationship, but it could be that he's leaving the choices to you out of deference to your age or perceived frailty. ;-) But if he just thinks you should choose because you know more about Europe than he does, then the suggestions above to involve him make a lot of sense.

Lucky guy, lucky grandma. Have fun!

One major caveat ...
Either strenuously exclude, or include at your peril, those cities where 20 year olds can easily find diversions on their own - Amsterdam, Berlin, Barcelona.