Existence of very advanced civilisations before known, recorded (mainstream) history.
It is more likely than not that there have been very advanced civilizations prior to known, recorded mainstream history.
We Just Got More Evidence a Large Meteorite Smashed Into Earth 12,800 Years Ago.
Platinum is known to be concentrated in meteorites, so when a lot of it is found in one place at one time, it could be a sign of a cosmic impact. Platinum spikes have been discovered in an ice core in Greenland as well as in areas as far apart as Europe, Western Asia, North America and even Patagonia in South America. These spikes all date to the same period of time.