I think one of the biggest mistakes that modern archaeologists, anthropologists and historians make is submitting to modern arrogance. You hear them say that such and such people couldn’t have possibly built this and that because they were so primitive/isolated/whatever to be that advanced. Well, clearly they were more advanced than you gave them credit for or they couldn’t have built it. I think it’s the last of the lingering belief in barbarism. For example: It’s hard to give Celts their due if the mind set is that European sophistication didn’t become widespread until the Romans.
(Stonehenge: Believed to have been built sometime between 3000 BCE and 2000 BCE)
Of course you have stupid people that go all Ancient Aliens and say stupid like “Aliens built Stonehenge, the pyramids and the Easter Island heads!”…which doesn’t even warrant a response.
(Eastern Island Heads AKA Mo’ai statues: Believed to have been erected between 1100 and 1680 BCE)
(The Great Pyramid of Giza: Built around 2560 BCE)
(Machu Picchu: Built around 1450 CE)
(The Great Pyramid of Cholula: Built around 3rd Century BCE)