You can find several hidden Fairies in The Legend of Zelda: Ocarina of Time throughout your quests. These Fairies reward you with powerful magic spells and power ups that are handy during combat. They either enhance your defense or increase your attacking prowess.
The Legend of Zelda: Ocarina of Time Great Fairy Fountains
Spin Attack Location. Take a left at the red flag down the death mountain trail. Climb up and jump across to the other side. Blow the rock blocking the path with a bomb, it’s all about timing your run and blasting the rock here. Cross down the path until Volcano is erupting.
Block the rocks with your Hylian shield and once they stop, walk down the mountain until volcano erupts again. Get to the end and continue making your way to the top. Once you reach the top, bomb the cracked wall leading you to the fairy.
Din’s Fire Location. Blow the rock which is next to gate of the Hyrule Castle, you’ll now see a passage which will lead you to this. You can equip it from the inventory and then press the C button to use it.
Farore’s Wind Location. Place a bomb beside the rock located at the opposite end of the frozen lake where Jabu-Jabu used to be. This will blow up the wall behind it leading to this Fairy Fountain.
Longer Magic Meter Location. Break the two rocks beside the entrance of the Death Mountain. You can go to the entrance of the Death Mountain by going through Darunia’s throne room.
Naryu’s Love Location. Go towards the Northern side of the Spirit Temple as the Adult Link, you will find a cracked tree which you need to bomb for this fountain. It grants you invincibility for a short period of time.
Half Damage Location. Lift up the giant pillar outside the Ganon’s Castle using Golden Gauntlet. Pillar is located in the same area you found Din’s fire in.