Zora's River, Zora's Domain, Lake Hylia, and Inside Jabu-Jabu

To get to Zora's River from Kakariko Village, go left after exiting the town and follow the river into the side of the mountain. Follow Zora's River all the way up to the waterfall at the end. Stand in front of the falls and play Zelda's Lullaby with your Ocarina to open the cave behind the waterfall. Jump across into the cave to reach Zora's Domain! Follow the dry path up to the Zora Shop and go up the hill and the stairs to reach King Zora. Stand on the platform and talk to him, and he'll tell you that Princess Ruto is missing! Get back down to the big lake downstairs in Zora's Domain. Dive in the water and swim towards the wall where the hill was, and go into the underwater hole because it leads to Lake Hylia! Once there, swim a little bit out and dive underwater again and take the Bottle with a message inside. Then, go back to Zora's Domain through that underwater passage you used to get there and go back up the hill and show King Zora the message. He'll then move over, letting you get into Zora's Fountain and Jabu-Jabu. Go down to the shallow sections of the Domain and catch a fish in your Bottle, then go behind King Zora and head to Zora's Fountain, home of Jabu-Jabu! Feed Jabu-Jabu the fish and he'll suck you into his insides. From the start, defeat all the enemies in the room, and then shoot the switch on the ceiling to open the door. Then, go right through the next room and enter the following room. (Don't worry, you'll come back to it later!) Talk to Princess Ruto and she'll walk away from you and fall into a hole in the floor! Save her by jumping into the hole after her and you'll land in the basement. Talk to her again and she'll finally let you carry her around. Go through the door behind you and go down the hallway while avoiding the floating bubbles. In the next room, drop into the middle area and throw Ruto onto the platform at the other side of the room. Then, press the switch to make the water rise, and swim up to reach the other side, too. Run through the next hallway, still avoiding the bubbles, and when you reach the door, turn around and shoot the switch in the ceiling to open it! Enter the next room and dodge the enemy's attacks while waiting for the floating platform to come down to the basement. When it comes, jump on and ride up to the first floor again where you were before. Walk along the ledge and enter the next room with the holes in the floor. This time, make your way to the other end of the room and enter the door to the next area. When the path splits, take the far right path and step on the switch. If the door shuts again if you get off the switch, place Ruto on the switch to keep it open for you. (This goes for all the switches in this area.) Defeat ALL the enemies in this room to get the Boomerang! Leave the room and take the second right and enter the room. Defeat the Green Parasite Tentacle swinging from the ceiling by aiming and throwing your Boomerang at its narrow weak spot a few times. After you defeat it, the big barrier in the room with the holes will disappear! Go back to the room with the holes, and drop into the new hole. You'll drop onto a ledge in the basement, which you couldn't reach otherwise. Enter the door there and when she asks you to, throw Ruto onto the platform so she can get the jewel there. The platform will take her up a couple floors and bring a giant octopus down to attack you! Defeat it by running around and around until you finally get behind it. Then, use the Boomerang and attack the weak spot with the sword. Repeat the process a few more times to defeat it, then climb onto the platform to get to the second floor. Go down the hallway and enter the next room. Use the Boomerang to make the shaky blocks stay still for a while, then jump across them to the other side! In the next room, jump onto the ledge and ride it down to the first floor again in that room you skipped earlier. This time, you're now able to reach the switch there. Get a crate from the nearby ledge and put it on the switch to keep the door open for you. Enter the next room and climb up the vines on the wall in back of the room. Stand a little bit back from the glass panel and use Z-Targeting to aim at the switch at the other side. Once your aim is set, throw the Boomerang so it swings around the glass and hits the switch! Now, get back down to the ground and enter the now opened door. Go down the hall and enter the next door to reach the boss, Barinade! Defeat it by using Z-Targeting on the huge tentacles on top of it and hitting them with your Boomerang. When the jellyfish guys start swinging around the room, use your sword to destroy them all. When they spin REALLY FAST around the boss, use the Boomerang and hope it hits the middle of the boss. Run in and attack with the sword a few times. Repeat the last few steps to defeat the boss! After you leave Jabu-Jabu, Ruto will give you Zora's Sapphire, the last Spiritual Stone!