The Legend of Zelda/Underworld/Quest 1/Dungeon 1

Objectives

 * Obtain the bow.
 * Obtain the wooden boomerang.
 * Beat Aquamentus.
 * Obtain a heart container.
 * Obtain the first Triforce piece.

Walkthrough

 * The entrance to this dungeon is found in the bottom right corner of section 5, just over the bridge which is a short distance north from where you begin the game.
 * Start by clearing the rooms both right and left of the entrance to obtain 2 keys.
 * Clear the next two rooms above the entrance, and enter the room to the right to obtain the compass. Both of the north walls in the compass room and the previous room can be bombed to reveal hidden pathways.
 * From the compass room, go left twice, and up once to arrive in a room with a single block. The door to the left can be opened by moving the block in any direction once all of the monsters are cleared.  The room to the left contains a man who gives you a hint as to the whereabouts of the triforce in this dungeon.
 * From the hint room, go right two rooms until you encounter some Gels guarding a map.
 * From the map room, go up twice, clearing each room as you go to obtain keys. Then head left and you'll enter a room with Traps in either corner and a stairwell in the center surrounded by blocks.  The left most block can be pushed aside so you can enter the stairwell.  Here you will find the bow.  You must still purchase arrows if you want to use it (and you may purchase them before the bow is found so that you can use it immediately.)
 * Return to the map room, and go right one room. Defeat all of the Goriyas to obtain the wooden boomerang.
 * From the boomerang room, go right one room. You can obtain a key here, but beware of the Wall Monsters.  They are enticed to come out whenever Link stands next to a wall.  If you are picked up by one, you will be deposited at the dungeon entrance.
 * From the Wall Monster room, go up to the next room to fight the boss.

Boss
Dungeon 2 >>
 * The boss is Aquamentus. You must stike him in the head six times with the Wooden Sword or three times with the White Sword.  Time your strikes between the energy orbs that he emits from his horn.  Only the Magic Shield will absorb the energy orbs.  Link will receive damage if he tries to block them with the regular shield.
 * Defeat him to earn a heart container. Enter the room to the right to obtain the first Triforce piece.