Hello everyone,
I have two that I've found so far that I think were camoed really well. The first one was moss on a tree:

What gave this one away was the fact that if you looked really closely you could see a nail that the owner used.

The above pic is that it looked like when you slid open the cover on it.
The other camo one is this one:

Can you see it? I walked by this one I don't know how many times before I picked up the piece of wood on the tree, and found this:

The cache was attached by fishing line to the piece of wood.