Go up to the top level and talk to Shamis Gatekeeper who is blocking the north exit.
Go talk to David Heavenguard who is in the corridor outside the inn. After the marriage(s), you can leave.
As you start along the mountain path, Quina will leave and Eiko will join.
Climb the vine at the top to find a Remedy.
Go right until you come to a strange statue. Take the Blue Stone and then go back to the start.
Go right, climb the vine there and go left to find another statue with a Red Stone and a Tent.
Continue on until you come to Suzuna the moogle.
Stiltzkin may be there too if you've been buying his stuff.
Take the right path and climb the ladder.
You'll get a good view of a big tree, but on the next screen you must fight Hilgigars.
After the fight, take the Yellow Stone from the statue and then head right.
Take the smaller right path to get to an Ether and another statue with a Green Stone.
Go back to Suzuna and go right this time.
If you put in all four colored stones into the big statue, you'll get a Moonstone.
Go back up the ladder and take the right path again, this time continuing on and out the exit.