[Out of the Box]

Originally Posted by EireEngineer

Basically, rapid technological innovation does not occur in isolated societies, but can occur when there is a broad geographical area with trade routes traversing it, as happened in Eurasia. It is highly unlikely that there would be a highly technological precursor society that was isolated to a small enough area not to have been found already.

The Pole shift hypothesis gives a possible explanation for what happened to this lost civilisation and why we haven't found it yet. If the Pole shift hypothesis is accurate, Antarctica would be a possible location for this lost civilisation and this would explain why we haven't found it yet.