Mysterious I thought...is the opening in the tree man made, or is it natural? Did some animal carve it out with it's teeth or claw? But then, it wouldn't be this perfect now would it? What does it seem to you? I thought it was a natural opening in the tree. My second thought, who could be living in there? Squirells? Rats? Never saw the bottom of a tree like this before. I thought it looked lovely with the little plants and a flower right in front of the opening in the tree, and the plants spreading sideways and upwards across the tree. I took this photo near the Niagara Falls, New York.