Sable and Her Brother

Finding Sable's Brother
This quest will grant you access to bombs.
First, visit Sable. She is located to the left of the mayor's house.
Sable will tell you her brother went to Creepers' Cavern in search of gold.
(Be sure the mayor has given you have access to Forest of Fayth.)
To find Sable's brother you need to find a hidden room in Creepers' Cavern.
This room can be found after defeating the Creeper.
Simply walk east right after you pass through the exit.
Most people walk west because they are in a hurry to get to the kingdom.
After you walk 1 screen to the east, you should see another entrance to the cavern.
Enter there and you will immediately find Sable's brother.
He tells you that he is trying to use bombs to find gold, but forgot his fuses.
If your teleport home is set to Dyce, simply use that.
Tell Sable you found her brother, and she will give you the fuses.
Simply take the fuses back to her brother, and he will give you some bombs to use.

Sable's brother will give you 15 bombs. Use the "B" button to set them.
Don't waste them, they are not easy to find at this point in the game.
Your bombs are only level 1 bombs, and will destroy tree trunks, some rocks, and a few walls.
Anything you destroy will reset if you leave the screen.
If you have a treasure chest key, bomb the rocks just north of Sable's brother.
There's a chest with more bombs in the room to the north.

Level 2 Bombs
To continue this quest line you need to navigate to the screen shown below:

This screen is found just east of the Division Desert.
At the top of this screen you'll see a small path that ends with some gravel.
Place a bomb on this gravel and a hidden staircase will appear.
Enter this secret cave and head north.
You'll find someone that has been trying to blast his way to a warp ring, but is having trouble.
He asks if you know of anyone that is knowledgeable about bombs.
Rush back to Sable's brother!
Once there, he will give you a bucket and a permit and tell you to gather some magma.
The permit grants you access to the Variable Volcano.
You should avoid the volcano unless you have a strong weapon and plenty of health.
(NOTE: You'll also need to use STUN or KICK on dragons. They have a deadly attack.)

Getting Magma
The volcano is northeast of the Multiple Mountains.
If you have trouble, use this MAP
Once inside the volcano, stay left and head north 3 screens.
You should arrive at a screen with an old man and a furnace.
In order to activate the furnace, you'll need to do some math.
(Be ready to find the perimeter of a quadrilateral.)
Take the bucket of magma back to Sable's brother, and he will upgrade your bomb's power.

Bomb: Level 2
Your upgraded bomb can now destroy the white pillars that are found in many areas.
The level 2 bomb also destroys a slightly larger area.
Destroying white pillars can, at times, yield diamonds.
(NOTE: The bomb can be upgraded to level 3, which blasts the entire screen!)