The Demon Cave.
The Demon Cave was deep underground, a veritable Underground World. However, contrary to the dark and damp environment one might expect, its depths were filled with vast fields of Earth Fire and lava. As a result, the temperature in the Underground World was actually higher than on the surface.
Special Spirit Flowers and Spirit Grasses also grew in this Underground World, and there was no shortage of water, supplied by subterranean rivers.
The Earth Demon Alien Race was a subterranean Alien Race that lived in this environment. They even cultivated special food sources here, allowing their race to sustain itself from one generation to the next.
Deep within the Demon Cave stood an exceptionally lavish palace. It was constructed entirely from Treasures found in the underground, all used for its adornment.
The Earth Demon Alien Race called it the Earth Palace, also known as the Demon Palace—the Underground Demon Palace!
