Is the Calm Lands the best place to level up characters? I am currently in the Calm Lands and I am looking ot grind so that I can more power ups for my party.

Even though it's been years since I last played FFX, I do remember indeed levelling up there, mostly on Malboros as I recall.

But mostly I think I just roamed around randomly killing anything that attacked me really - I don't remember going after anything specific.