Two of us want to fly into Nice - probably late March 2022 - then take a scenic route, with opportunities for stopovers in Cinque Terre, then Siena as the destination. Would appreciate any suggestions for:
1. How long to stay and what to do in Nice
2. Best way to travel for scenery along the way to Cinque Terre / Siena
3. Best places to stop along the way
4. Any ideas and suggestions would be welcome.
5. Also, suggestions for next places to visit - Florence, etc. and best way to travel - scenic and economical - top things to do - would be most welcome.

Merci / Grazie mille!

Train from Nice to LaSpezia, then back to 5T. Unless you want to detour to the Alps then the route is along the coast the entire way. As for "best" places to stop along the way a lot depends on your interests and time. It could range from stops at places like Monaco, Genoa, Pisa and /or Florence if you wanted to see those cities, to nowhere if your time is limited.

Between Nice and the Cinque Terre there are many tunnels to pass through so the trip may not be as scenic as you hope.
Traveling by car from Cinque Terre to Siena we went down the coast and then via Volterra which is a worthwhile stop. There is a parking garage on the hillside before you reach the top of the town.

The answer on how long to stay in Nice depends on the length of your total trip. There are many side trips from Nice, by public transit or car. Monaco, for example, is best done as a day trip by public transit. You can spend a few days or two weeks, it all depends on your time and your interests (we have a place in Nice).

Since one way drop off fees and occasional insurance restrictions can impact your ability to drive in Italy, some take a train to a destination like San Remo and pick up a car there. The autoroute is a ways up the hill (and btw, in a rain storm coming off the sea, not so fun), has a lot of tunnels and is not as scenic. The coastal route is much more scenic but slow, due to the numerous towns. There are some small villages and resort towns that are quite nice, and best reached by car. There are some nice stretches of road, as well, with broad coastal vistas and winding curves.

After Florence, I think your question is where are you going to fly out of? Milan? If the answer is Rome/FCO, then you can reverse your order and go from the CT to Lucca (which I love) and then to Florence, then south to San San Gimignano and Sienna. From there onward to southern Tuscany (Montalcino/Montepulciano) and Umbria (e.g. Orvieto)

Nice to Ventimiglia by local train then onward train to genoa, change there for Monterosso in CT. Or go Ventimiglia-Milan-Florence-Siena.
See https://www.seat61.com/trains-and-ro...y-by-train.htm
Yes it's scenic - that page has some photos taken from the train!

There aree 4 ferry itineraries between Nice and Livorno, all with stopovers at Corsica: makes only sense if you want to spend at least one night in Corsica.
Points of interest along the coastal (Riviera) itinerary: Museo del Mare, Acquarium and historic city center of Genoa, scenic village of Portofino, Marble caves at Carrara, historic centers of Massa Marittima, Lucca and Pisa, boat ride between Levanto and La Spezia (during the season only)

If "economical" is a big concern, a less expensive option may be to fly in and out of Florence. Take the train to the CT and back to Florence and then pick up a rental car at the Florence train station. It's only about an hour from Florence to Sienna and spend the next days using Siena (or nearby) as a base and drive around exploring using the rental car.

Worth checking out the difference in cost - in both airfare as well as rental car costs.

There remains a small problem, however. there are no direct flights from Nice to Florence or Pisa.
A train ride from Nicevia Ventimiglia to Cinque Terre costs about 30 EUR and lasts about 5 hrs https://www.raileurope.com/
A low cost flight from Nice via another airport to Pisa or Florence costs around 100 EUR and lasts 5-9 hrs.
A train ride from Pisa airport to Cinque Terre lasts 1 1/2 hrs and costs 13 EUR.

Menton in France and Portofino in Italy are both exceptional places to stop.

Thank you!

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Thank you!