What Does This Lead To/how Do I Find What It Mentions

So inside a cave in the Canyon of the Lost and I found a thing written on signs with a button under that looks like this:


What is this 'Seal' that the button opens? Help?

 

An Easter egg that means absolutely NOTHING.
My group thought it was a ??? lead.

 

nicefind.avi

 

Ah, so that button is just there and doesn't do a single thing then? Dang, and here I thought I'd found a cool thing that would give me an epic loot chest XD

 

Ooooo I've been looking for this, coords?

 

No, it does open a chamber that has a big face in it, but it's still useless.
If you really wanna know where it is, it's in a building up the mountain and across the bridge, except the building is more like a cave, then a piston will open up a coal block(?) wall.