What is this green pipe with an open end sticking out of the ground?
Try picking it up.

No, really, are you sure it's actually connected from something? It looks like a leftover piece of material that was leaning against the structure until it got kind of stuck in the ground.

Maybe it's a random piece of junk stuck into the ground by another bidder, to trick the current holder into accepting a lower price. If this proves to be the case then you should draw cracks on the windows and bid even lower.