“Who even manufactures a fake tennis court tarp anyway?”
And he is wealthy enough to put a real court down as a cover up so why is this fake tarp there and what do they do when it is rolled up. I don’t totally buy the burial theory as it would be easier to just take a boat out- unless he can’t part with his trophies. Or is he burying evidence of the notables who have visited for future reference/blackmail?
First question is to hide whatever they are doing from a casual aerial observer.
I doubt they roll it all the way up, just far enough to access what is below or add to what is below. Looks like steps on the downhill side.