You mean like the Pyramids?
Although, I’m more talking about the stone cities and finely cut stone walls that are worldwide, we can include the pyramids. The only reason why they say the Egyptians did it is because it’s in Egypt and the assumption is that it’s the work of man.
Although I do believe it is also the work of man, it may not be the work of post-Flood man, or at least soon after the Flood man. The time line of the building of the pyramids is only a comparatively few years after the flood, which is interesting to me.