1 jan 75000 ano antes da era comum - Adam's Calendar

Descrição:

some theories:
rock formation as a calendaring system
estimated to be 75000 years old

https://en.wikipedia.org/wiki/Blaauboschkraal_stone_ruins

http://realhistoryww.com/world_history/ancient/Misc/Adams_Calendar/Adams_Calendar.htm

Adicionado na linha do tempo:

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