Top Ten Legend of Zelda: A Link to the Past Dungeons

It might be very challenging (for beginners, at least), but it's worth going through because right after it, there's one of the most epic final fights in the series.

It's definitely the hardest dungeon in the game! " and that my friends is why it's the last dungeon."

Without any doubt. Just that sensation of about to be beating the game, I loved it

My 3rd favorite Zelda dungeon of all time, behind turtle rock and the earth temple (i don't count ganon's tower as a dungeon

I just love the setting of this dungeon.

Can someone help me? I don't know English very well, but I'll try my best.
I am right now in the Swamp Palace. And at one point, I made the water go up. However, there was a skull with a key down there, but now I can't get it because Link just swims!
What can I do? Do I have to restart the entire game or is there a way? If there is, please reply, because I'm not willing to start the game from the beginning just for one dungeon!