Why is Jabu Jabu's Belly from Oracle of Ages not on this list? I thought it was incredibly difficult playing it as a kid, and recently re-playing it on the Nintendo Switch Online service didn't change my opinion. Water-based puzzles, having a dungeon with three floors and on top of that areas you can only access while the waterlevel is a certain level. It's different from the Water Temple of OoT since you can actually swim underwater in Oracle of Ages where the controls change drastically. Anyone who has played that game knows how... interesting the controls in the water become once you have the Mermaid Suit.
For me honestly, I found majoras mask's great bay temple to be the hardest. It was confusing and had extremely diffucult bosses. The water temple was kind of easy foe me even as a kid. Not the master quest version though, that one was brutal
City in the sky, snowpeak, and ancient cistern really aren't that hard compared to others. Also why aren't turtle rock and or ice palace from link to the past on here? Those ones are aggravating.