If the dodgy stonework isn’t enough to put you off entering the cairn, perhaps this story from Martin McCarthy’s Ancient Scotland site will be.
There is a tale of a visitor to this tomb who squeezed his way in with great effort, and then exitted with much greater speed and skill after--so he says--something kicked him in the kidneys. Yes, it’s a stupid superstitious story; but after visiting the tomb you can’t help but wonder....