A large cavern full of Reoniban Mushrooms shrubs & large pillars like Reoniban Crystals located beneath the Eokya Coast of Aquineon on Reptutopia Continent. This large cavern was was formed about 45 million years ago since afters millions years later after the Cataclysm forming huge numbers of basalts & large productions Reoniban that spread across the water bodies to the seas. There also presence of archeological evidence that ancient structures are buried above the cavern that were sunken up; it is unknown what kind of lost city was since the discovery of Eokya Coast. However, geological studies shows there's an escapement dropping of Reoniban that it's connected from the geothermal tunnels from Mt. Neoriv, which everything producing life on Aquineon will be dropping down the underground through the tunnels that I'll take to underground rivers into some lakes caverns. This allow to grew plenty of biodiversity of mushrooms & plants for nocturnal creatures, even for marine creatures that are in this cavern. This giant large pillars of Reoniban crystals formation are used a purpose to flow up the sources & control up the stability of planet crust which connects geothermal. Noting that this large crystals has no uses for regenerations since it has that only purpose on controlling up the crust likely and there not actively. One thing certainly this helps supports life enough to create photosynthesis to lush up the entire cavern for it after millions years forming.

There's also a natural geothermal site that connects to this caverns that relate on control up the stability of the planet, which it's seems oddly that those large crystal may act up like electromagnetics in theory. If so, this may also use alternative way to produce power naturally. This seems evidence that how some structures that are buried within this cavern that may add up as an early site of use of power sources. However, this is un-conclusive for this beautiful cavern, there still more hidden evidences on how the people made this way early times. Still, even more clues comes, this is one of the secrets & gorgeous site that support life this cavern for the planet.