Instructions
Walk through the east exit from the starting room and follow the twisting corridor until it deposits you in a room with train tracks on the ground.
Follow the tracks and turn south when you are able to find a chest holding Scale armor. Turn back north and continue following the tracks until you come across a heal pad and a save point next to each other. Heal and save your game.
Enter the northern room and engage the "Earth Smasher" boss you find there. Defeat the boss and then head through the western door.
Open the chest to the west, then head south and east to return to the first room. Head back to the save point and save your game. Instead of a door to the north you will find five switches, each corresponding to a different type of minecart hauler.
Select the "Steady" hauler as your transportation. You will now have to guide the hauler along the tracks.
Keep your speed at around 25 kph until you are prompted to select which way you wish to turn. Slow down to around 20 and take the left turn.
Turn right when prompted again and slow down even more. Rocks will start to drop from above and you need to go slowly to avoid them. After the rocks, speed back up to 25 to get through the gates.
Slow down under 25 as soon as you pass through the gates, then take the left turn when prompted. This will get you out of the caverns.