You can barely adequately visit Paris and Barcelona in 10 days. I think you need to cut out at least 1/2 of what you want to do.

Otherwise you may want to consider a guided tour - groups like Contika are catered to a younger group and cover alot of ground (expect early wake ups and lots of time on the bus though).

Start charting your city change each time you move. Barcelona airport to hotel--hotel to train station to Nice train station to hotel. You could probably stay in Nice and commute to Monte Carlo--maybe one day each--then transit to Nice train station to Paris to hotel to oubound Paris airport. That's a lot of changes in a short time --lots of effort. Consider fewer destinations--Barcelona is a great place to explore for 3/4 days.

what do you like?

I would stick with Barcelona and Paris as your bases...too much to go to the French Riviera IMO and it will probably be too cold to go to the beach.

We want to see the sights and enjoy our time. Castles, museums, main attractions, good food, etc. We don't need to see everything and not looking for a relaxing vacation. We'll come back at a later time to spend more time in each location. We live in florida so the beach isn't that big of a deal. May need to skip French Riviera?
Thanks macanimals for your input- didn't think about the changing so much and the time it takes.

We didn't have time to visit it (but saw it from the bus) -- but Barcelona looks to have a great beach, itself. As part of a longer trip, we spent 4 nights/5 days in Paris and 3 nights/3 days in Barcelona. Tip of the iceberg, really, but it gave us at least an overall feel for both. That's almost your 10 days right there...and there's always daytrips you can take from either location, if you want to get away from the cities. So I'd agree with the idea of sticking to those two cities as your bases.

We took the hotel train (overnight train) from Paris to Barcelona. I see many folks advise against the night trains; we, on the other hand, really enjoyed them. We did pay more and get a single and a double compartment for the three of us, on that route. It was lovely to go to bed in France and wake up at our destination in Spain the next morning. Anyway, it's something to think about.

I would just split the time between Paris and Barcelona. Barcelona has tons of nightlife which will keep you busier than you think. Stick with day trips from the 2 cities as Nice and Monaco don't really fit in without travelling out of your way.

We're looking at Barcelona, Nice, Monte Carlo, and Paris in October.>

10 days it can be done

Barcelona 3 days
Take overnight train to Nice (take regional train to French border then from Cebere/Hendaye overnight train to Nice - or in the day it would take all day.
3 days in Nice - including day trip to Monte Carlo
Train to Paris
4 days in Paris

Or fly Barcelona to Nice

Trains are really modern in both countries - for lots on train travel in France and spain i always highlight these info-laden sites - www.seat61.com; www.budgeteuropetravel.com and www.ricksteves.com

Hi; I like Pal's thoughts. Not sure if you can fly non-stop to Nice, but you can to Marseille on www.spanair.com in one hour. Very inexpensive. Then rent a car for three days and drive to Nice. You can find a great town to visit on the way. Richard

www.whichbudget.com and www.skyscanner.net link one to cheaper airlines flying any routes. And from Marseilles if you do not want to rent a car there are frequent trains to Marseilles - but i like the idea of driving via the likes of dream Cassis on its idyllic calanque and rugged coast to Nice via St-Tropez.