Part 9/16:
The excavations indicated a construction date around 230 BC—during the Western Han Dynasty—placing their origin over 2,200 years in the past. If correct, this predates many known Chinese engineering feats and conflicts with the complete absence of historical documentation or ancient texts mentioning such extensive underground structures. The Chinese Empire, famous for meticulous recordkeeping, had no records of their construction, leading to theories that they might have been deliberately erased or hidden from history, possibly as state secrets.