Zelda 1 - Walkthrough of Dungeon 8 of Quest 2: The Large Spiral (Zelda I NES mini)
Map of the labyrinth "The Large Spiral": Dungeon 8 of Quest 2 from Zelda I (The Legend Of Zelda NES mini)

Normally you should arrive at this palace with 1 key. It's not mandatory but it will save you time (and I wrote this walkthrough assuming you arrive with a key). If you don't have one, you will pick up the magic wand at the end rather than the beginning. However, it is mandatory to have bait to get past the red Goriya in H3. Other than that, the palace is fairly easy, but it would be good to have 100 rubies to buy 4 extra bombs, which will also allow you to top up on bombs before the boss (3 Dodongos). This level is fairly easy as it contains neither Wizzrobes nor Darknuts.

Go up, push the stone and take the secret passage to A2 while watching out for red bubbles. Walk through the bottom wall and go down using your key. Kill the hands coming out of the walls so you can push the middle stone to the right, then take the staircase to find the magic wand. If you didn't have a key, you will redo this section after completing the palace (you should have the magic key by then).

Go up, head right and place a bomb at the bottom then go down. Kill all the blue Goriyas to find the map. Go back up, kill all the enemies and push the middle stone to the left, then take the passage that brings you back near the start, at H6 (2 rooms above the entrance).

Head straight up to the "grumble, grumble" (the Goriya blocking your way), give it the bait and go up again. Kill the 4 Keeses, take the compass and go up once more.

Kill the blue Goriyas to get a key and open the left door that you need to go through. Kill all the blue Goriyas again to go left. Place a bomb on the left wall then go left.

Go through the left door after killing all the hands if you don't have all your bombs. Kill the 3 Dodongos to open the door and head left (if you didn't pick up the bombs just before, go back for them before going through the door). Collect the key and push the middle block to the left to take the secret passage.

Open the left door with the key you just found and kill all the Stalfos, then push the middle block to find the magic key. Go back right, go down, push the block downward and go through the left door. Walk through the bottom wall and go right twice. Kill all the blue Goriyas, take the bomb and then the underground passage.

Place a bomb at the bottom and go down, then go down again while avoiding the Goriyas (or killing them for 5 rubies). Then kill Aquamentus to go through the left door. Kill the 4 Wall-Masters and push the middle block to the right to go through the left door. Buy the 4-bomb extension and return to the room with the last secret passage (2 rooms right and 2 rooms up). Don't kill the 2 fire centipedes and open the top door to access the boss.

The Triforce is guarded by 3 Dodongos. As usual, place yourself directly in front of them and place a bomb for them to eat. If you didn't have a key at the start of the level, don't forget that you will need to re-enter this dungeon to go get the magic wand (see paragraph 1).

Small Key : H1, C1
Dungeon Map : B4
Compass : H2
Magical Rod : A4
Magical Key : A5
More Bombs : D7

You are ready to continue the adventure. Here is a save file (an 8 KB .sav file).