Milan to Riomaggiore by train.

Trenitalia shows runs via both. Either is fine. There are even runs that go via Sestri Levante or Rapello and don't go at all require train changes at Genoa or La Spezia. Expect 3.5hrs-4.0hrs for the run.

Susan, The "short answer" is that it will depend on which train you choose. You'll most likely transit through Genova, possibly with a change of trains. What time of day do you prefer to leave Milan? A couple of choices you could consider would be a departure at 08:10, arriving Riomaggiore at 12:08 (one change at La Spezia) or a departure at 12:10, arriving at 15:39 (one change at Monterosso). There are lots of other choices, but some have two or three changes and some involve a 10-minute walk from one part of the station in Genova to another. I usually prefer the easiest method, if circumstances allow. You can check the Trenitalia website for details on all the trains on that route. Reservations will probably be compulsory for some portion of the journey. The local C.T. trains are usually Regionale, so DON'T forget to validate your ticket! Happy travels!

Thanks, a big help!

Riomaggiore is between Genoa and La Spezia, but much closer to La Spezia (just few minutes from La Spezia in fact). Coming from Milan, via train, you will always go through Genoa and then proceed East toward Riomaggiore and La Spezia. That doesn't mean you have to change trains in Genoa. You might be changing trains at Sestri or Rapallo, which are between Genoa and Riomaggiore. In some cases you will stay on the train all the way to La Spezia, in other words past Riomaggiore, then at La Spezia, change train and go back to Riomaggiore.

Should be interesting!