My tree is all walled in.  It is very strong.  I build it in honor of a famous artist who makes art out of nature.  It is a tree that I am working on getting to know, the linden.  The bottom is pretty much like a little fort made out of sticks and leaves.  It is pretty cool.  I wonder how high I can make it without my sculpture falling apart.  I wonder if I can make a roof in it.