[usrusr]

Yeah, completely undiscovered does not happen, with the exception perhaps of battle sites which seem to keep catching archeologists by surprise. What does happen is discoveries of the kind "so we dug up this old thing, because it's in the way of some project, and we discovered that it contains identifiable traces of something much older that we did not expect."

The concept we both seem to be tiptoeing around is the idea that the best conservation approach is leaving it in the ground, for future archeologists to explore or not explore. I believe that this is a central principle of the modern approach to archeology, and one we laymen struggle to really take in. Yes, there are many sites known to science, but not analyzed to destruction by science.