The honest mind must wonder what Homo sapiens was doing in the 200,000 or so years between his appearance on earth and the dawn of history ca. 3,000 B.C.
There is evidence of great civilizations during this period. If this is true, most of the structures and artifacts have been effaced or devoured by the earth, but traces remain to be discovered, and miracles of technology, yet to be developed, will no doubt reveal some of them.
Arguments against their existence are the use of stone alone in the construction of ancient buildings and the absence of metal artifacts, some but not all, of which, it would seem, would have been devoured.
On the other hand, such things as the Mahabharata, the Ur battery, the Piri Reis map, the Planes of Nasca, the weathering of the Sphinx, the legend of Atlantis, et al. cannot be ignored by truth seekers. The Trojan War was considered mythology until Heinrich Schliemann produced convincing evidence of its true existence.