Get rid of the Keeses, the Babas and the Bokoblin (if you get caught by the plant, do a spin attack to get free and get rid of it). To get 10 rupees, climb the vines to the left after the entrance and open the chest. Break the cage containing the monkey and use your Slingshot to get rid of the two Skulltulas on the vines. Then climb the vines and open the door.
Walk down on the slope and get rid of the big Skulltula using your sword (hit its front when it is ready to attack you). Use your Slingshot, look up and shoot at the three balls to get twice 5 rupees. Go northwest of the map, attack the Bombling with your sword or by raising your shield and by touching it with it, then quickly carry the bomb and throw it at the wooden door, in the middle of the northern wall. Loot 20 rupees from the chest, then come back to where the Skulltula was. Use your Lantern to light the torches on each of the four corners of the platform. (You have to shake the Lantern in front of each torch). Head north, pick up the Dungeon Map in the chest and open the door.
The bridge being broken by the nasty monkey, come back and follow the nice monkey. Stand right in front of the animal, jump towards it and let go to go across. Open the door.
Go right and get rid of the Bombling which will destroy the wall. Throw pots to get some rupees but also to find Ooccoo! (who can warp you out of the dungeon if you wish) Go on to the left and burn down the web. Get rid of the plant, jump on the wooden platforms and open the northern door.
Go on the bridge and open the door. Pick up the Small Key in the chest and come back to the room were the monkey stayed.
Go right, use the Slingshot to make the Skulltula fall and finish it off with your sword if needed. Jump straight ahead and unlock the door west on the map.
Another monkey is locked up! Come down to the right and look at the monkey. Run and bump into the pole, then twice more as it is moving. Fight the two Bokoblins that showed up, then follow the monkeys. Jump towards them to cross and walk again through the last door. (You can get 10 rupees from the northeast chest.)
Cross again the eastern door, then with the monkey's help, go to the east door. Burn down the web and open the door.
Go to the middle of the room, climb the stairs and turn left. Get rid of the Bombling, then carry the bomb, run and throw it at the Big Baba to the bottom (northeast of the map). Afterward, jump to the other side. Aim the Slingshot at the two Skulltulas further on the vines, then jump towards the vines and climb up. Open the door.
Use the Z-lock and hit the Big Baba several times. When the "head" is done for, use the bomb from one of the two enemies and throw it in the middle of the plant. Pick up the Small Key, free the monkey and get out.
Get rid of the Bombling to the left, take the bomb and throw it at the big plant underneath you. Jump and open the chest to find a Piece of Heart! then come back to the Bombling near the top of the stairs to the northwest. Get rid of it once more, pick up the bomb, run eastward, jump to the other side and throw the bomb at the rock above you. Climb up and open the northeast door.
Climb down right or left and bump into the pole with a chest by rolling against it. Pick up the Small Key from the chest, and the 5 rupees atop another pole. Cross the pond using the footbridge while avoiding Tile Worms or by swimming right of the footbridge. Climb the vines north to find 20 rupees in a chest. Light the two torches, climb the stairs, then get rid of the big Skulltula. Free the monkey and backtrack two rooms west.
Follow all four monkeys and open the door. Thanks to them, you can go across this room and open the next door.
There is your first mini-boss! Get rid of the plants, but do your best to always keep the monkey in sight. The moment he throws his Boomerang, rush to the pole where he is standing to make him fall down. Hit him several times with your sword and do everything twice more to defeat him. This way you will get the Gale Boomerang which the monkey left behind! Go to the exit and throw the Gale Boomerang three times on the spinning pinwheel over the door to open it and exit.
Take the footbridge on the left, then throw the Gale Boomerang at the next footbridge's pinwheel to be able to cross to the right. Throw the Gale Boomerang at the cage's string to free another monkey and keep on crossing the place to the southeast. Open the door.
You end up in a known room. Go back to the east room. Aim for the slabs using Z and use the Gale Boomerang to unhook them, then cross towards the torches. Throw the Gale Boomerang at these two torches to put them out and make stairs come down. Open the chest to find another Piece of Heart! then leave this room. Go back once more west where the first big Skulltula was.
Look for a chest on the ceiling. Throw the Gale Boomerang at the string then open the chest and pick up the Compass! Go on west, go left and cross the room towards a gate southwest on the map, either by jumping on the wooden platforms or climbing on the southern vines. Notice the Z on the ground, then take out your Gale Boomerang, aim and lock on each pinwheel atop the poles to form a Z pattern starting from the northeast one. Open the chest to find the Big Key! (To get 10 rupees/the letter A stamp, go to the southwest end of this room by swimming.) Go north and open the door.
Use the footbridge to cross (the monkey will follow you) and open the door. Get on another footbridge using the Boomerang and open the door.
Get on the right footbridge and throw your Gale Boomerang at the pinwheel of the footbridge on which you stand. Go to the next one and reiterate. Go towards east, use your Gale Boomerang to get rid of the two Skulltulas, then climb the vines, go right and drop down at the end. Get rid of another Skulltula further on the right and climb. Open the door east.
Get rid of the two plants, then take out your Gale Boomerang, aim at the Bombling north, release and throw the bomb at the plant in the water to the south. Jump and pick up the Small Key from the chest and come back to the middle of the room. Aim once more at the Bombling, lock it and aim and lock at the big rock to the west and throw your Gale Boomerang, so the bomb will fly to the rock and blow it up. (You can also, like in any other Zelda game, use the Gale Boomerang to get a bomb and throw it at the rock when it's about to blow up! - which is harder.) Climb the vines and get rid of the foe. From the ledge, pick up another bomb and drop it in front of the rock between the two torches. Once the monkey is free, come back west, then south by spinning the footbridges.
Throw the Gale Boomerang at the footbridge's pinwheels. Get on it and hit once more the pinwheel to spin. Unlock the west door.
Look at the slabs and climb on the one at the northeast corner (on the map) while facing south, to be propelled up to the northern platform. Pick up 20 rupees/the letter N stamp from the chest, then go to the corner of this platform from where you can see an opening (northwest) and jump over the tiles in this direction. (You can also use your Gale Boomerang to lift the slabs, then hit the enemies hiding under them). Clear out the big Skulltula at the end of the corridor, then the two small ones on the vines. Climb on it and stand right in front of the gate. Aim and lock both pinwheels using Z and throw the Gale Boomerang to free the monkey. Go to the other side, jump in middle of the slabs and get out.
Open the door to the east, attack the two hanging spiders, then burn down the web which covers the hole on the north side of the room while standing on it (shake several times your Lantern if needed). Hit the cage with your sword a few times to free the monkey, then jump on the vines, climb and get out. (You can blow up the baba for a red rupee if you wish.)
Get on the footbridge, use the Gale Boomerang to make it spin and open the door north. Use the "monkey rope" to go across the gap, then break pots to refill your hearts and capture the fairy in an empty bottle. Unlock the Boss door.
Twilit Parasite: Diababa
Use your Gale Boomerang to aim and lock at a bomb, then aim and lock at one of the two plants and throw the Gale Boomerang so the bomb explodes in the plant's jaw. Do the same with the second plant, then the main plant barges in, along with a monkey a few moments later. Following the same technique, lock the monkey's bomb, then lock the plant and throw the Gale Boomerang so the plant swallows the bomb! When its head falls down, run towards it and strike its eye several times with your sword. Get back to avoid its spurts of purple poison, then repeat those actions against the main plant to defeat the boss. After the monkey's apparition, you can again destroy the two small plants, but this is optional.
You will receive your first Fused Shadow! what Midna was looking for. She says that there are three in total. Pick up the Heart Container and get close to Midna to get out.