what is it?

Have I shown this before?  We found it in our backyard, years ago, with privet growing through it, making it impossible to remove.  We went on a privet rampage and the stump has finally rotted and released it's prey.  

We like it but we don't know what the item is.  Any ideas?  I've leaned it against the mailbox, one piece on each side.  My daylilies are growing around it now.

And, here is the *completed* wall!  Landscaping which requires no maintenance will follow.  I'll need to dig up many more natives from generous friends.  The twenty year old, strong and hard working neighbor has no summer job right now.  He is eager for money and worked two days to help me finish.  Now he's asking for more work and I'm complying.  The ivy at the top of the hill must go.  If we can get rid of it at the flat top, the playset could go up there and free up some yard.  Plus, the playset is the view out my dining room window, which isn't the best.