There are very large pyramid structures (bigger than the Great Pyramid) recently found in South America which have been dated to 25,000 BC. Naturally these finds (among hosts of other finds) are discounted as anything which disturbs the academic grant-generating meme is either discounted, discredited, ignored, reburied, or destroyed.
Be glad it was ‘allowed’ to be found.
1) in height?
2) in volume of stone?
3) in ground area (footprint)?
I'm moderately familiar with central & south American prehistoric structures; they built some amazing things!
So, to what site(s) are you referring?
And, are the "pyramids" of stone -- or, some other material?