The Forest Temple was originally supposed to be called the Wind Temple which is the reason for the Gale Boomerang but I don't get why you wouldn't find something that creates wind in the sky. Instead you find it in the hands of a large monkey.None of the dungeons in Twilight Princess were that hard, but I thought that the City in the Sky was the hardest in the game. I felt it was similar to the Forest Temple in TP (bit indoors and bit outdoors), but took it to a higher difficulty level. The theme around the dungeon was creative and fun, and the item that went along with it worked really well too.
I don't find the Lakebed Temple to be hard. I only find it annoying. I dread going to both Lakebed Temple and Snowpeak Ruins. Lakebed Temple is confusing, way to big to find your way around, and also the annoying part comes in with the fact that if you fall of the edge of one of the walls in the main room you'll fall down to a group of Skullfish and also that you can't roll up the stairs.The Lakebed Temple. By far, The Lakebed Temple. Having to change the staircase in the main room was confusing enough for me, let alone the entire dungeon. Complete with a main room as confusing as the Grand Staircase room in Hogwarts, too many rooms, puzzles, and switches, and topped off with a difficult (but fun) boss, The Lakebed Temple is (and will always be) the dungeon I wish I could have skipped.