If you have a Kupo Nut in your inventory there is an optional thing that you can do before heading to Cleyra. Head back to Gizamaluke’s Grotto and go back to the room with the bell, go through the door on the right side and talk to Moguta. When he asks for the Kupo Nut give it to him and he will give you a Phoenix Pinion. Each time you get a Kupo Nut you should go back and give it to him. Leave Gizamaluke’s Grotto to get back to the world map.
You should take the time now to equip your characters with new equipment. Equip the Mythril Dagger to Zidane so he can learn his Bandit ability, which makes stealing the better items from enemies easier. Equip Chain Plate and Power Belt to Freya and activate the Counter and HP+10% abilities. Now go back to Burmecia on the world map and go west from there until you come to the desert. The giant Sandstorm should be visible in the distance, approach it and then enter.
To get to the top of Cleyra you first have to move through the trunk. Head up the stairs and pull the lever to open the door. Proceed through the door way and into the next room. Go towards the right and open the chest to get a Phoenix Down. Equip Vivi with the Ice staff if you have it, even if he isn’t done learning the ability from his previous item. This is because some of the enemies are easier to kill if you cast an Ice spell on them. Go up the steps and proceed into the next area, as you enter move down and open the hidden chest at the bottom to get Magician Shoes. Move up and search next to the flowing sand and open the chest to retrieve an Ice Staff. Exit this room to the right.
Follow the path up to the top, move into the room and open the chest to retrieve an Ether. Move to the end and examine the hole. Choose the ‘Put hand into hole’ option. The room beneath will be flooded with sand. Move back outside and follow the path down back to the entrance. Climb up the vines until you are in the newly accessible room. Move through this room, climb up the slope to the right and open the chest to find a Tent. Now move down and to the far left there is a chest that contains a Needle Fork. Climb back up and talk to Monev the moogle at the end of the path to save your game. You should also have a letter for him and he will give you a Kupo Nut in return for delivering it. You will not get a Kupo Nut if you didn’t already give it to the Moogle family in Gizamaluke’s Grotto.
Move up the path to the left, before following the sign pointing towards Cleyra follow the opposite path and open the chest at the end for a Flame Staff. Head back down and follow the other path and cross the bridge. You can probably see the chest visible from behind the column in the center of this room. Approach it and open it to retrieve Desert Boots. Move to the right of this cavern and open the visible chest for a Remedy. Continue along the path into the top right and continue following it until you see a ‘!’, open the chest to get a Mythril Vest. Now exit this area by going through the opening at the top of the room.
Open the chest to the left to retrieve Mythril Gloves, continue following the path and when you reach the lever pull it. Now move back to the previous screen and then back into the cavern. Go to the left and follow the path up, open the chest to your right to find a Potion. First take the path to the right at the fork and open the chest to get an Elixir. Go back and take the left path this time, cautiously move along the paths between the sand pits and open the two chests to get a Hi-Potion and 900 Gil. If you fall in the sand pit mash X repeatedly to get out. If you fail to get out you will have to fight some enemies.
Maneuver your way to the other side of this room and head into the next area through the opening. Follow the path and open the chest at the end to receive Gysahl Greens. When you are finished climb up the ladder.