Need some help in the Jungle/Bamboo forest area

[Nilla]

I was making progress in the bamboo forest area but i've hit a wall. After completing all the puzzles on the panel that pops out of the ground (see here[s128.photobucket.com]), a pink cable lights up. However, i cannot find where that cable goes. I've followed it but it just dead ends not that far away (see here[s128.photobucket.com]). I've searched all around in the immediate area (even looking up in the trees since the yellow cable does run there) but i cannot tell where i am supposed to go to progress. Any clues?

Also, in the same area i opened the gate that leads to a cave like chamber (see here[s128.photobucket.com]) that is close by but there is a hexagonal puzzle there that i cannot interact with (see here[s128.photobucket.com]). When i click on it nothing happens. What are you supposed to do here?

[MASTAN]

That pink cable leads somewhere important, search more. Hint - bamboo forest. Cable is just underground, to make search not so easy. But it shows general direction of search.

That hexagonal thing you've found is not interactive. But there is a place where it's needed.
Actually there are several others in different caves.

[jussr]

For the hexagonal things, keep hold of those screenshots. Or drawings, if this game makes you regress to your Myst days like it did me!

As for where to go next... as a general rule, if you can't find anything after searching your immediate area, perhaps it's time to broaden your search?