Nei! Vanntempelet er ganske lett! (PLEASE let this adjective be the proper one, declined properly.)
In the Zelda games, there is usually one water level. They're always pretty difficult because you have to think about the map in terms of 3D instead of 2D, and what would happen to the map when it's covered in water up to several different points. Oh, and the levels take place in a temple :)
Ocarina of Times Water Temple is the best. The two bosses are the best. Miss that game.
And here I thought it was referencing the water temple levels in Tomb Raider.