Once you are on the shores of the Forgotten Continent, head towards the west. You should be able to see the citadel in the distance, use the mini-map if you are having trouble finding the right direction. Approach Esto Gaza and press X to enter. When you enter approach the citadel in the background and enter. Once the Bishop is finished talking head to the right. Talk to the shopkeeper to look at what he is selling. There is a lot of good equipment in this shop, make sure to stock up on them while you have the chance! Keep in mind that once you get to Disc 4 you will not be able to return here.
Make sure that you buy the Octagon Rod for Vivi, this will teach him all of the aga spells: Thundaga, Blizzaga and Firaga. The new lance for Freya is weaker if you managed to snatch the Holy Lance from Ark, it teaches the Six Dragons ability which isn’t very reliable. Once you are done viewing the items move around the shop from left to right and search by the right side of the desk to find a Wing Edge for Amarant. Exit this area and head back to the previous room. Proceed up the steps, talk to Mogrika to save your game, she has received a letter from Artemicion, Read it with her and then speak with her again, she has a letter for you to deliver.
Proceed through to the right, follow the path to enter Mount Gulug.