giant cups?

Has anybody else found any giant cups? I found one in the room near the waterfall section where there are two sets of stairs and in the middle there are three archways blocked off by bricks. also in the room there is a square pillar of wood that shoots you high up when you stand on it. of the three aforementioned archways between the two sets of stairs, go to the middle one; it's much larger than the other two and notice it's a different shade to the other two archways? try pushing/pulling to the far side of it and there is a room behind it!
In the middle of the room is a circular platform, stand yorda on it and it sinks as a giant cup rises.

If anyone else has found any giant cups, fancy letting me know where they are and what the point of them is?

Cheers