The hardest dungeon in Zelda history would be the Stone Tower Temple from Majora's Mask. It was actually pretty annoying how you had to flip the dungeon over in most parts. You practically had to use all your masks, and the temple mask, the Giants Mask, could only be used in the boss room! However, it was truly a test for those who are most experienced at Zelda. The Spirit Temple, from Ocarina of Time, was also a pain in the neck, because you had to beat the first half as a child, and the next as a adult! Iron Knuckle, the mini-boss was a hard hitter and deals four hearts of damage in normal quest, and eight in master quest. Twinrova, could also deal up to seven and a half hearts of damage! These two temples were truly a test for the hero of time himself.