corsica?

That's hard to say. The island is still pretty wild and time is needed to see the beauty of this pirates' wilderness. But from Nice take a ferry boat to Calvi and stay there for three days. There is enough to explore in that town and the beach is beautiful, too. SNCM would be the ferry boat line for that crossing. From Calvi day trip along the North coast using what they refer to as railroad. The ride itself is fun and you get to see a lot.

Corsica is beautiful! My sister and I spent about 2 1/2 days there in october and it was sunny and warm enough to swim in the sea. Loved it! I think it would be worth it to go for 3 days. We arrived in Paris, then flew to Ajaccio, Corsica, arriving in the early afternoon. We stayed with my sister's friend for two nights. We visited some beaches and sites on the west coast, then on the 3rd night, at about 10:00pm, got on the overnight ferry (on which we had booked a cabin) to go from Ajaccio to Toulon (near Marseilles). We didn't have to deal with renting a car or taking a car on the ferry since our friend had one we could use, so the fares were cheaper.
We used the Corsica Ferries company (an Italian run ferry) over the SNCM (French) because their site seemed easier to me to navigate and also because I'd read a suggestion to avoid the French one in case they decide to go on strike (which is not too uncommon with the transportation systems in France).