Help me find an anime.

Hi.

I'm looking for an anime I think I saw in the late 90s. I'm assuming the anime is pre 2000, it could be 2000/2001, maybe, but I think I saw it in the late 90s.

Anyway I was just a kid so I don't remember much. What I do remember is as follows.

There was a girl, most likely the lead, she was in a castle of some sort, could have been a white, clean castle. She was like alone. What I remember clearly and what sticks out the most is that there was a golden pool and the main character went for a swim in it. Then I remember another character came up to the castle and they hanged around, talked and then they went into a forest or a garden of some sort. They might have gotten lost there.

I'm thinking it was a feature but it could be a series.

That's pretty much all I remember, it's not much to go by but if anyone has a clue I would be grateful.