@piggo I've only been to 2-3 sites where such large conglomerations of stonework have come off intact. I frankly worry more about some of the crumbly places like Shrule I've visited where the stonework hasn't been attended to at all and you've got rocks just sitting loose dangling half off the decaying parapet.
Shrule had head sized stones recently embedded in the ground scattered all about due to the recent hurricane.