You are right about that - a few people have said it was pots, and that is what it is alright. We worked out it was an asphalt machine as @wadeo007 pointed out below - great work with the details, and thank you for that - was wondering what it was. If Rusty Sackleford finds like air filtration holes, where there should not be any, then that would be the thing I would be wanting to see. I.e., vents that go underground etc., but I am doubtful if that will be found - fact is, if there were tunnels, and I don't know 100%, then they are long covered up now as well with any surface evidence of what would be clear evidence of tunnels. Can't wait for the docs to be released by the court this week - even though, no doubt everything will be redacted and names will be missing. Might be still some clues inside.