Eternal Ring

The Secret Dungeon:
Best Place to Get Invulnerbility and Max XP. There is a hidden four-floored dungeon in this game. To go there, you need a Dark or Light Magic Spell Ring. Go to the beach where you start the game, go to the left and you'll find a door that is locked. Cast a Dark or Light Spell on the door, and it should open. Inside this dungeon, you'll find some pretty hard monsters. They can kill you in one hit, so be very careful. There are Lvl 5 Magical Stones of all kind, Magic Rings (in the 3rd floor, there is a bird that give them infinitely), Special Rings (including the Mirage Edge, that makes you hit 4 times instead of one), and the Eternal Sword (you have to kill a monster in the last floor to get it). This is also a great way to gain tons of XP. The best way is to kill the big birds in 2nd floor. The best way to kill these birds is to get Dragon Fangs by killing the white crabs on the 4th floor. Every time you kill them, they'll drop a Dragon Fang that will raise your stats by one. Keep using these until all your stats reach 255, and you'll be strong enough to never die.