"Passano i secoli."
I suppose that, like in Spanish, both forms are allowed: "I secoli passano" = "Passano i secoli".
I think I've heard that in Italian, it's all about where you want the emphasis. So, they grammatically mean the same thing, but if you're stressing the PASSING of the centuries, you'd put "passano" first, but if you're stressing that it's the CENTURIES that pass, you'd put "I secoli" first. I'm no expert, though, so I might be wrong.
I'm guessing it's like "they pass, the centuries", so that "they" refers to the centuries. Would be nice to hear from a native speaker on this one.