There's one on Mt. Coronet somewhere... You enter from the North side, and surf across the southern pool of water to find it. I don't know how to be more descriptive, sorry.
Fable - The only reason I don't like the turn-based system on a 3-D environment is because on the previous 3-D pokemon games (stadium/battle/revolution/whatever), it always seemed like it took too long for a battle to happen. It just doesn't have the same realism i'd want in a 3-D pokemon game, because in the anime, if a pokemon does Surf, it drowns out the pokemon, and you have to think fast and attack back; not they attack with surf, the water disappears, you attack with razor leaf, leaves disappear. If they could make an exciting turn base battle system in 3-D, i'd be totally for it in the game.