My wife and I are planning a trip to Nice and on to Marseille for a total of 7 -8 days. Is train the best or only way to get between the 2 cities? Any suggestions on must see in those cities? Any hiking / walking paths in particular we should definitely do?
You don't need a car in either city and many day trip destinations along the French Riviera are served by frequent trains and buses. Direct trains from Nice to Marseille take 2.5 hours and run about hourly. Tickets for TGV departures are sold for reserved dates and times, but unreserved regional trains get there in the same amount of time. I have not been to the city of Marseille, but can strongly recommend nearby Cassis and its Calenques. In this area, Rick's Provence/Riviera guidebook covers more (including Cassis and Marseille) than does his wider France book.