Proceed north from Mr. Holzoff’s cabin when you are ready to begin your ascent up the cliff.
You will need to keep an eye on your body temperature as you work your way up the cliffs. Cloud will be okay as long as his temperature stays between 26 and 38 degrees. If it falls below 26 degrees he will pass out and wake up back in Mr. Holzoff’s cabin.
For safety measures it is recommended that you keep your body temperature at 30 degrees or higher during your climb.
There is an enemy in this area called a Stilva (pictured below). This enemy has two Enemy Skills that you can learn on your 
Enemy Skill Materia.
The first and most important skill is called Trine which can be difficult to learn later on in the game. Stilva will never use Trine on its own though - you will have to use Manipulate from the Manipulate Materia on it and have it cast the move on your party.
The second is called Magic Breath which it will use on your party members as a regular attack. The third and last Enemy Skill that you can learn is Bad Breath from the Malboros that roam the area.
The first section of Gaea’s Cliff is entirely linear. Stop off at each of the waypoints with the red flags to reheat yourself. Continue along until you reach the first cave. The temperature gauge will disappear after you enter the cave and you will no longer be required to heat yourself up.
Travel north under the bridge and through the door leading into the next section of the cave. Take a left and then travel south when you reach the corner to re-enter the previous room.
Cross the bridge and continue going right to enter a secret room. Use the screenshots below to help guide you. There is a 
Ribbon accessory in the treasure chest of this hidden room.
This is one of the most powerful accessories in the game. Do not miss this item! In fact, a number of the enemies in the Gaea Cliff’s will hit your party with status effects. It would be a good idea to equip this Ribbon on one of your characters as soon as you pick it up.
Go north immediately after you exit the secret cave to find a treasure chest that contains a 
Javelin; a new weapon for Cid that offers double Materia growth.
Proceed through the doorway to the left of the treasure chest and continue north until you reach the upper level. Examine the boulder and choose to “Push the rock over”. This boulder will remove the icicles that previously were blocking the pathway below.
Backtrack all the way to the lower level and follow the newly opened ice pathway. Follow the pathway through the cave and around to the right side of the room. Continue down the next pathway out of the Inside of Gaea’s Cliff leading back out to the face of the cliff.
There are several pathways that you can take while climbing the cliff this time that lead to dead ends. Go straight up when you reach the first fork in the pathway and choose to go right when you reach the second fork.
The second cave you reach is much larger. On the far wall is a 
Save Point where you can save your game. There is a treasure chest in this area which contains an 
Elixir.
Take the doorway on the right side of the room that leads back outside and follow the pathway all the way around to the right.
When you arrive back inside the cave you should start off by grabbing the treasure chest on the right side of the screen that contains a 
Fire Armlet.
As you walk from the right side to the left side of the screen you will be thrown into battle each time you touch one of the four icicles hanging from the roof.
You need to defeat all four of them and as you defeat them they will drop down to the level below creating a pathway that you can hop across. Using the Trine or Beta Enemy Skill from your Enemy Skill Materia is a fast way to end the fights quickly.
Do not jump down to the level below until you have defeated all of the Icicles and obtained the treasure chest on the other side of the room which contains a Megalixir which is incorrectly referred to as a “Last Elixir” in the game (corrected in the PlayStation 4 version of the game).
Walk along the edge of the pathway and once you get close to the doorway you will be given the option to “Jump down to the room below”. Select yes to jump down.
There is a treasure chest to the left of the Save Point which is now available as a reward for defeating all four Icicles. The treasure chest contains a Speed Source.
Hop along the pathway created by the fallen icicles to reach the doorway at the back of the room (just to the right of the Save Point). The treasure chest on this pathway contains an 
Enhance Sword for Cloud.
The Enhance Sword contains a ton of paired Materia Slots but it has terrible Attack and Attack % stats. This sword is only good if you wish to have Cloud focusing on magic spells and summons as it will allow you to load him up with Materia.Organics is better though if you wish to utilize Cloud’s standard attacks. Follow the pathway around to the left side this time.
One last cliff face to climb. Choose to continue upward ("Go up") at both of the intersections. Use the Save Point when you reach the next cave as there is a boss battle coming up. You can also touch the pool of water to the right of the Save Point to fully refill your HP and MP.
There are enemies in this area called Blue Dragons and you can win Dragon Armlets for defeating them. Dragon Armlets are fairly powerful pieces of armor and are especially helpful for the next boss fight.
Preparation: Schizo, an upcoming boss battle, is an entirely elemental-based boss. Its attacks will typically come in the form of Ice and Fire-based spells. Equip your characters with the following items in preparation for the battle depending on what you have in your inventory:
Aurora ArmletsFire ArmletsBolt ArmletsDragon ArmletsFire Ring or Ice Ring
Fire Materia or Ice Materia paired with 
Elemental Materia on your armor. This step is excessive if you have already equipped each of your team members with some combination of the items above.Proceed to the right of the Save Point when you are ready.
HP: 18,000 (left) + 18,000 (right)
Reward: Dragon Fang
This boss battle is all about the preparation put in before the fight (included in the list above). Keep an eye out for the non-elemental attacks, use Big Guard to keep your team well protected and make sure to have Steal Materia equipped and to steal a Protect Ring from Schizo.
A video demonstration of this battle is included below for reference:
Go back and refill your HP and MP at the glowing lake and save your game at the Save Point. Proceed down the hallway and climb the last cliff afterwards towards the Whirlwind Maze.
