Castle Tower

Castle Tower is the 4th dungeon in the intended dungeon order of the game, and it's the final dungeon in the Light World phase of the game.

Access

Castle Tower is accessed by using the center door on the Hyrule Castle ramparts. The door is protected by a magic barrier that will electrocute Link if he makes contact with it.

The typical way through the barrier is to hit it with the Master Sword, which can be gotten from the Lost Woods after collecting the three pendants from the other Light World dungeons.

With major glitches

If the player is using major glitches, there are some other ways to access the dungeon door. The barrier can be cut with any sword greater than the Master Sword, and the Magic Cape allows Link to walk straight through it.

These items are typically unavailable to Link at this point in the game but can be accessed early through the use of major glitches.