In this series of three shots, I've shown different aspects of our day trip to Cinque Terre. Where and what Cinque Terre is; that's discussed in the first of the shots.
Whatever Cinque Terre might have been in the days of yore and whatever vestiges of that remain... what it is now, is tourism. If you walk down the streets you aren't stepping back in time, you're stepping out of the way of a throng of tourists coming back the other way. The passenger levels on the trains are comparable to Sydney's City Circle and even worse, I suspect, if multiple cruise ships hit La Spezia and passengers swarm north on the trains. The closest I came to a place without other tourists was when I climbed the hill behind the town and even there I encountered others, as I recounted in yesterday's photo.
Monterosso is the one with the best beach and, consequently the most tourism, as we can see here. Part of the beach is private, apparently, though I'm not sure who owns it.
One final parting tip if you are planning your own day trip to Cinque Terre from Firenze.
Don't.
Unless you have no other choice and would not see the place otherwise (which is the boat that we were in), the experience will be sub-optimal. You will arrive too late (even when you leave Firenze at 07:00) and leave too early (and still not get back to Firenze until 19:00) and spend too little time at each spot to appreciate it. I would not do this trip again, though that's easy to say when you've done it and therefore had the experience. But if you're restricting yourself to the north of Italia, you would be far better off trying to spend at least one night here. Two would be better.