I’m pretty good at jumping to conclusions. I should have taken up archeology.
As far as I can tell if you come across something that you are not sure what it is you label it "toy" or "religious artifact". You can't go wrong as long as you insist that all civilizations advance exactly the same way and have exactly the same values.
Never consider that raising fruit and nut trees is a lot easier and in some places more practical then raising grain type crops or that fish farms can support a rather large population.
That will allow you to declare that someplace was a "untouched wilderness" even when you have eyewitness reports that only a few hundred of years back there were large groups of people living there.