For the entertainment of replaying to the "current day History" I must reply:
Current man creates big things called "buildings". These "buildings" have been quite successful in both scaring vast tracts of land, and staying where man left them for a long time: Stonehenge, Pyramids etc. My guess (and it can only be a guess) is future historians (again, assuming such a fascination exists then) will find a great interest in the etchings left in these man made structures, and will treasure signs like "Fire escape", "Ladies Toilet" and "Thanks you for shopping with us!". I suspect that rust lined holes in the back of random rock walls will be of little interest to them.
Sandbagging is a dirty game