Originally Posted by
YVR Cockroach
If I did stay in Pavia or somewhere down the line, I would buy a seperate ticket from Milano to there.
What I was saying is that I have a ticket for Day X between Milano and La Spezia on Train Y (a specific train (in this case, an IC) at a specific time on Day X). What I am saying is that I presume that on Day X, I can get on and off train Y at any points between the specifically-ticketed points (Milan and La Spezia). Pavia and Monterosso happen to be stops for train Y on Day X between Milan and La Spezia.
And yes, it is Monterosso that we're planning to get off at.
No, you might be able to get on and off quickly for a macchiato or a glass of wine, but you will either have a four hour time limit on your ticket. If the next train will get you to your final destination within four hours of departure, that is OK. If not, then you will be ticketless. If you are on a train with assigned seats, it will say carroza, or car number, seat number and time. If the conductor comes and checks your ticket and you are not on that particular train, you are considered to be without a valid ticket. If on a train with an assigned seat on a specific date and time, you must stay on that train.
You mentioned that your final destination is Cinque Terre, but you are going to La Spezia. Monterosso is one of the five towns of the Cinque Terre. Do you really want to go past the Cinque Terre to La Spezia, then turn around and go back to the Cinque Terre?
Once you are in Monterosso you are in Cinque Terre. There is a local train that connects the five towns, and that actually ends in its last stop outside the Cinque Terre in La Spezia. Whatever your final destination is in Cinque Terre, you can get off in Monterosso, go for a swim, do what you want to do on their excellent beach, then take the local train for a few euros to whichever one of the other four Cinque Terre towns you are staying at (I assume you are not staying at Monterosso, because you said you just want to stop there); Riomaggiore, Manorola, Corniglia, or Vernazza.
If you are specifically going to La Spezia then your destination is not Cinque Terre because it is not one of the five towns. You might be day tripping to CT, which is OK if it is not in high season. But no, sometimes people take a shot at pleading ignorance if they are on the wrong train, but you usually won't get away with it. You are going to have an assigned train even if you don't have an assigned seat on base fare, or you will have an assigned seat and train. You can't get on and off. If you really want to get off on Monterosso you can buy a ticket that takes you there, then take the local train to La Spezia for a few euros.