OK.. I will give my tip. The little paddle wheel things across the vally, once you get those spinning, climb on the belts that they are turning. Took me a while to figure it out but it is a must to solve it.
HINT You don't go all the way up in one shot. Actually it is split into three sections. If you haven't found it, go to the telescope where you can look at the maze of pipes. 1st look in the middle about 1/3 of the way up. 2nd, look about half way up on the left.