Location: Future 05
Items: None
There are two reasons I decided to add this. One, there was no end all, it was just four random things. Two, there was just one thing that seemed like you should be able to help with, that seemed like a place of significance. For those who skipped ahead to read this, it's finally time to storm the castle in the future. The reward? Another gold statue and the east side of the town is permanently free of monsters. And that's everything, probably (could have skipped optional or class dungeons, or missed heart container pieces or magic containers).
Note that beating this dungeon will give you an explanation of what really happened. See part four of the storyline if want to know.
You can find the entrance in the future town: the bombable door west of the castle. In the present, this was the home of the two men who sold you more bombs, but now it's an abandoned cave. The door to their bedroom is permanently shut, but use the candle and find the cracks in the wall. Bomb your way deeper into the cave, and when you get to the stairs there's an obvious bomb spot to the left. That path lets you bomb your way into the bedroom to find a purple rupee, and talk to a soldier trying to figure out the riddle of downstairs. To be fair, it's a tough riddle for somebody without the context you have.
Now check out downstairs. The music and structure have changed, but there's no branches yet. Proceed to the room with four barriers, and walk towards them. If you've gotten the gilded statue in the side quest, the opposite door's shutter will open. Then if you've beaten secrent dungeon 1, the first barrier will disappear. Secret 2, second barrier, etc. I figure that the Lost Woods secret dungeon is the hardest to beat, so I changed that to secret 4 so it would be the final barrier. When all four barriers are removed, you can obviously proceed (or go back to the soldier trying to figure it out and he will congratulate you).
Now we're back to needing keys, but there isn't much in the cave. First branch, go west if you need a key, and east if you have the magic key. Then bomb the east wall, and get a second key. Go south and then east. Follow the path until it loops back to the west, and you'll reach some stairs up. This is the secret entrance to the castle, mostly forgotten about long ago, and given up by the rest aside from that one soldier.
This dungeon is pretty simplistic, but there is a 3x3 sub-basement that didn't exist previously. If you don't have the magic key, collect keys on the first floor. One is in the room behind the thrones, one is in the northwest guarded by a ton of dodongos, one is in the northeast and downstairs to the side-view basement (be sure to bring a bomb), and then the southwest and downstairs you'll find a key each in two of the three bedrooms. Now you should have five keys.
Go through the key door in the southeast. If you don't have the magic key, go upstairs (north) and collect two more keys on the second floor, in the northwest kitchen and in the southeast shop, and then go back to the first floor. Non-knights can check out the areas, although they're empty.
Now that you're back up to six keys, you can go south in the southwest into the basement jail. Go north to the cells, and now there's a door leading downstairs to the sub-basement training area behind a locked gate. There's only one way to go through this whole section, west west south south east east north west, and there's the boss key. Go east and north and north to go back upstairs to the basement. Go south and south again to go upstairs to the first floor. Go north to the second floor. Go west, and then north through the boss door.
Kill the boss and go north to the final victory room. It's populated with people from the various secret money caves (did you find all eight groups of them?), and you get the final song. This is the only song not from a video game, "Istanbul (not Constantinople)" by They Might Be Giants, which some might know from Tiny Toons. John and John of TMBG are in that end room with their guitar and accordian. I guarantee you've heard at least one of their theme songs to The Daily Show, Austin Powers Dr Evil, Malcolm in the Middle, Mickey Mouse Clubhouse ('00s), Cartoon Planet, America's Most Wanted ('10s), The Oblo...