![](https://art.gedolab.com/wp/wp-content/uploads/2023/05/undiscovered_underground_ruins-02a-09-D15-150x150.jpg)
Undiscovered Underground Ruins (未発見の地下遺跡)
There is a possibility that undiscovered underground ruins still exist. There are still places that have not been excavated or that may be discovered as excavation technology advances.
There is a possibility that undiscovered underground ruins still exist. There are still places that have not been excavated or that may be discovered as excavation technology advances.