Take off your Iron Boots to float to the top in order to enter the Temple. You are now in a central room with a golden structure in the middle and a lot of Hookshot points around.

Put on your Iron Boots and drop down to the bottom. Go through the only accessible door, it has a blue tiled hallway. You'll meet Ruto, your Zora Fiancee, she tells you that there are 3 places to change the water level. She has you follow her. Take off your Iron Boots and float up to the top floor. In the room you'll see a Triforce symbol on the wall and a barred door. Play Zelda's Lullaby in front of the Triforce symbol. This lowers the water. Use Din's Fire to light the 4 torches in the room. This will open the barred door. Kill the 3 Stalfos. Then, hookshot the middle of the plaque on the wall. This will reveal a treasure chest with the DUNGEON MAP. Exit that room and drop down the hole.

You can now light the two torches on either side of the door. Use Din's Fire. Go through the door, you'll have to face a Spike. Use your shield on it and then, slash it. There are also 2 Lizalfos in the room. Kill everything and open the treasure chest that appears. You have the COMPASS. Exit out the door, and go back to the central room, with the golden structure in the middle.

Go in the door that is in the central structure. Use your Hookshot to get up a level. There is a Water Switch here. Play Zelda's Lullaby in front of the Triforce symbol. This raises the water level and raises a block for you to get on. Jump across to the door. Exit. You are now back in the central room.

Put on your Iron Boots and go back down to the bottom and into the room where you met Ruto. Float up and go into the room. Use your Hookshot on the plaque on the wall. This will reveal a treasure chest with the LONGSHOT in it. The Longshot is a longer version of your Hookshot. Go back to the central room and float up.

Go through the only open room/door with the blue hallway. Hookshot up to the next floor and grab a small crate. Fall down and go back through the hallway to the central room. Make a jump right across the water to the central golden structure. Run to the other side of the structure and find the blue switch. Place the small crate on the blue switch. Go through the now open door across from you.

There are a lot of crates in this room, and a Lizalfos to kill. Break all the crates and one will reveal a crystal switch. Hit the switch with your sword. This will make a couple of Hookshot points. Use your Longshot on the Hookshot point through the hole in the ceiling. Destroy the crates to reveal the Gold Skulltula. Go through the door. This is another Water Switch. Play Zelda's Lullaby to raise the water level to the top.

Go into the central golden structure through the door on the second level. You'll have to put on your Iron Boots to get there.

Float to the top of the central structure. Play the Song of Time to lower the grey/blue block. Jump up to it and use Din's Fire to light the two torches.

Put on the boots and sink all the way down in the central structure. Drop down through the hole and go through the hallway.

Work your way through until you see two green grates above you. Break crates near the second green grate to reveal a crystal switch. Use your Longshot on the switch. All this does is open the grate, which leads to nowhere. It's a deadend. Go back to the crystal switch and, just past it, there are two brown "stairs". Step on them and it will reveal another crystal switch. Longshot the switch. This will open the other green grate above you. Longshot up to the hookshot point and use your Longshot in the middle of the plaque on the wall. This reveals a small treasure chest with a Small Key in it.

Exit this area and go back to the central structure. Float up to the second fl. entrance and go through the door into the main room. Float all the way to the top and go through the chained door on the West of your map.

Go to the edge of the door and look directly up. You'll see a switch. Hit it with your Longshot. This will make a bunch of hookshot points on the waterfall in front of you. Now, fall/slide down to the platform below you. There are 2 hookshot points, one above the other, on the left side of the waterfall. Longshot up to the higher one, and you'll land on the lower one. From here, watch where Navi is. She is hovering around the plaque on the wall. Longshot the middle of the plaque and a large hookshot point will emerge in the middle. Use it to get up to the door. Go through the door.

Drop down and fight the 3 Stalfos. This will raise the bars on the door that you came in and it will raise some Hookshot points. Longshot up to the platforms and make your way around by climbing over the purple dog statue. Longshot over to the next purple dog statue. Look up and Longshot up to the purple dog statue above you. Longshot across the spikes using the hookshot point in the ceiling. Go through the door.

Go to the tree in the middle of this surreal reflective room. You will have to face a shadow of yourself. Target your "dark" self and hack away. After you kill your dark reflection, the bars on the doors will open. Go into the building in the North of your map.

Longshot the plaque on the wall to reveal open the green grate. Drop down. You are now facing a swift river with some hookshot points. Put on your boots and run down the river. Avoid the whirlpools, you can run past them, but it is tricky. If you need to, use the hookshot points. When you get to the end, go through the passageway.

You'll be looking down into a room. Longshot down to the safe landing below you and to the left. Drop into the water below you and sink to the bottom. Longshot up to the hookshot point on the ceiling of the underwater passageway. Break the crates. Hookshot up to the next level using the hookshot point in the ceiling and get out of the water. There are 2 big crates and 3 small ones in this room. There are also 2 torches in the ceiling. Use Din's Fire to light them. This opens a door, back out in the room you were just in. Exit out Longshot up to the now open door. Go through.

There is a crystal switch, hit it. This causes a water spout to come out of the floor. Drop down onto the unactive water spout. Use your Longshot to activate the crystal switch from where you are. Ride the water spout to the top and use a Din's Fire. This will light the torches on the other side of the green grate and allow you access to the Boss Key. Jump across and get the BOSS KEY.

Exit back out by sinking, going through the hallway, and floating up. You'll be in the central room again.

Get up to the top level of the central structure and Longshot over to the Northern door using the purple dog statue as a hookshot point. You'll see the Boss Door and a bunch of sliding spikes. Above the Boss Door, you'll see a switch. Shoot an arrow at the switch. This will give you two hookshot points to use to get by the spikey things. Go through the door.

Boss Fight: Morpha
Morpha has a red core to him. You need to use your Longshot on the red core, which will pull it out. Stay on the outside edge of the room (the platforms become a pain) and keep it targeted. When it pauses, use your Longshot. It will bring the red core near you and then, you can slash it with your sword. Do this 6 or 7 times and you'll have defeated Morpha! Grab the Heart Container and step into the light. You will receive the Water Medallion.

There will be quite a cutscene, then you will watch as Lake Hylia fills up. Sheik will disappear. At this point, run over to the rising sun and shoot an arrow directly at it. For this, you will receive FIRE ARROWS.

Now, it's time to seek out The Lens of Truth, Under the Well.