Where do you find Masamune in Golden Sun 2?

In "Golden Sun: The Lost Age," you can find the Masamune in the optional dungeon known as the "Lands of the Living" or "Lands of the Dead." Specifically, it is located in the area called "The Great Sea," where you need to navigate through the dungeon to reach the room containing the legendary sWord. Once you solve the puzzles and defeat enemies, you can acquire the Masamune, which is one of the most powerful weapons in the game.