10 days in Spain or Italy, or BOTH

Save Barcelona for another time.
Stick to one country Italy since it is your first time and you only have 10 days.

I've been visiting Mallorca roughly two weeks a year over the last decade and still haven't explored it all. Granted, my holidays there are a more relaxed affair with an average of one sight a day so a ten day trip could easily be filled by Mallorca alone. I would stick to one country and don't forget to allow a day for travel between most cities. An equal split between Rome and the Amalfi Coast would be a good option.

Definitely stick to just one country, and if possible, just 2 locations. Remember that on your first day you'll be dealing with jet lag. If this is your first trip, you won't know how badly it affects you until you're there. And each change of location eats up at least half a day, reducing your time to explore and enjoy. Splitting your time between Rome and the AC will easily fill your time, and still leave many sights there still unseen. Consider a multicity ticket into Rome and out of Naples to reduce your travel time. Otherwise you would have to return to Rome the evening before your return flight.

Check The 13 Day Italy My Way Tour...the itinerary looks like it would work for you. The 11 Day Spain My Way Tour looks good, too.

One country in this time frame, maybe two bases. I haven't been south of Rome, but you can find a base down there. Barcelona another time. You don't want to spend a third of your days packing, checking out, moving to another city, checking in, unpacking, and so forth.

I would stick to Italy and focus on Rome and Sorrento/Amalfi Coast area.

For schedule ideas, look at the itineraries for: (1) Rick's 7-day Best of Rome tour; and (2) the back-half of Rick's 13-Day Best of South Italy.

I highly suggest that you include a visit to Pompeii. It's an easy stop en route to Sorrento (via Napoli and the Circumvesuviana). I believe you can store luggage at Pompeii's west entrance. Finish the day with the easy half-hour or so ride to Sorrento.

Thank you all! This is super helpful. After discussing some of the feedback with my sisters, we may look into Paris and French Riviera for the whole trip. Any suggestions are welcome! Thank you.

I’ve spent a lot of time in both Paris and Nice. Tell me what kinds of things you like to do and I’ll share my experiences. Will you take a train from Paris to Nice? About a 5 hour trip but no changes on the TGV. Let me know how I can help.

We have been to both countries several times and highly recommend only ONE country. For 10 days, you will be lucky to do Rome and Florence (perhaps stretch it to include Venice).