Ancient Castle of Ikana
Go on, turn left and go through the doorway to the east that leads to the castle. Put on your Gibdo's Mask and go to the middle of the room. Melt the ice on the eye, which unblocks the round door to the north, and go on. As Deku Link, hit the diamond, then go through the room running and hit the other diamond. When the platforms moves up again, go to the flower and dive in it. Then when the platform is down again, jump and fly to the pillar. Remove your mask, step on the switch and open the door quickly. Here, fly towards left and step on the switch to unblock the door. Use your Lens of Truth to find an ice block, jump on it, get rid of the Skulltula with an arrow, then jump onto the central platform. Get rid of the Skulltula to the northeast as well, then jump onto the platform, then towards the door. Get in, run and avoid the skulls, or your sword will be unusable for a short time. Climb the stairs and go on to get to the roof.
Climb on the small edge on the right and walk south on the wall. When you see a switch on a pillar, use the Deku flower nearby to get to it and step on the switch, which moves a block hiding a hole. Then jump onto another platform with a flower and use it to fly back to the first flower, then on the wall. Come back north and look for a diamond along with a Piece of Heart in the far northeast corner. Stand in front of the first pillar surrounded by flames then hit the diamond using your Hookshot, quickly jump on the pillar now accessible and use the two Deku flowers to get the heart. Now you can drop to the ground.
You will soon need a Powder Keg, so return to Clock Town, go to the Bomb Shop and buy a Powder Keg.
Go back to the Ikana Canyon, head right and take the passage to the left of the Ikana's Castle doors to be back in the Ancient Castle of Ikana. Go left, hit the diamond, then use the Mirror Shield to light the sun block and go on. If Tatl warns you of a presence, wear your Garo's Mask and use your shield to fight off the Garo who will tell you about a secret route in the Ikana Castle. Then come back inside the building.
Shoot a fire arrow at the eye on the right and open the right door. Stand under the light using your Mirror Shield to redirect the light on the hand which will divide into three small hands, then quickly strike them or use the mirror again to destroy them before they reunite. Next, redirect the light towards the sun, go on and open the next door. Now you need to fight another Wizzrobe which this time is breathing fire. Use the same strategy as before (strike him once he's getting tangible and when they are four, focus on the one that isn't translucent). Then open the eastern door wearing your Gibdo's Mask, break the pots if you need hearts, and follow the passage leading to the roof. Head right and look for a place where the ground is cracked. Place your Powder Keg on it, put on your Gibdo Mask, then jump in the hole. Now that the room is lighted, use your shield on the wall with a sun.
King Igos du Ikana & Servants
Get in the centre of the room to start the fight. First, shoot fire arrows at both curtains so the light can come back in. Next, attack both skeletons with your sword while being near the windows as the servants fear the light. Then as soon as one of them is on the ground, go on the other side of the room and use your shield to direct light at him. When they are both defeated, the king stands up. He has different moves, so it is better to beat him quickly. Like his servants, you can only hit him with your sword, so put on your Bunny Hood and try to hit him on the sides or in his back. When he's finally on the ground, direct the light at him to defeat him. After the bicker between the two skeletons, the Ikana King says that you broke the spell cast upon him and that you should now seal the doors of the Stone Tower. To help you, he grants you a "soldier who has no heart" and teaches you the Elegy of Emptiness. Leave the castle.
Go to the northeast part of the canyon. The entrance to the Stone Tower is located to the right of the Spring Water Cave.