Theory 3: A protective wall to shield the settlement from lava flows

In 864, during the Heian period, Mount Fuji erupted, producing the Aokigahara lava flow.

Another idea is that the wall was built so that, if a lava flow of the same scale were to occur again, the settlement would not be swallowed up.

However, it is said that none of these theories are conclusive.

To be continued in Part 3

➡Click here for Part 1