The archaeological facts show that civilizations from other continents did travel to the Americas long before Columbus ever arrived.
Dr. Barry Fell in his work America B.C. shows that evidence. There are ancient artifacts in the Americas to show the ancient Egyptians, Greeks, Romans, and Pheonecians treked to the Americas. But of course the mainstream Harvard school of archeaology denies all that.
It's not by coincedence that evidence of Babylonian-Canaanite Baal worship from the East is also found in the ancient Americas. At the tower of Babel event, when God confused the one tongue, peoples were then scattered to the four corners of the earth. That's how the ancient peoples of American populated the Americas. Canaanite-Hebrews words can be found in languages of the ancient peoples of the Americas.
But as for the existence of a higher technology and an imparting of occult knowledge to ancient peoples, see the book of Enoch which goes into greater detail of what the fallen angels did on earth during the days of Noah.
The fallen angels coming to earth to take wives of the daughters of men per Gen.6 is not some fairy tale. It is God's Word. And no doubt that event is the real origin of the ancient mythologies of gods found among ancient civilzations. It explains why God brought a world-wide flood upon the earth to end that working in Noah's day.
And maybe some here to need to review the following coming event of our near future...
Rev 12:7-12
7 And there was war in heaven: Michael and his angels fought against the dragon; and the dragon fought and his angels,
8 And prevailed not; neither was their place found any more in heaven.
9 And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
10 And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of His Christ: for the accuser of our brethren is cast down, which accused them before our God day and night.
11 And they overcame him by the blood of the Lamb, and by the word of their testimony; and they loved not their lives unto the death.
12 Therefore rejoice, ye heavens, and ye that dwell in them. Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.
(KJV)