The Opal Sea ,at first glance, travelers might mistake this vast blue expanse as the shore, but most of this city wide structure is entirely made out of pure blue crystals, running deep into the depths of the world. During the turbulent formation of the planet, these massive city wide minerals were forged and as the eons passed, gargantuan Crystals crop up all over the globe and civilizations developed around it.
some mined its bountiful resources for millenias without barely even putting a scratch in its whole mass, others considered it a holy land where their deities reside in, guarding it aggressively from foreign bandits and raiders. folktales emerged from various cultures. stories of monstrous behemoths or other-worldly denizens lurking in the center of the structure, but no one can really ever know for sure as a journey towards the center of the mineral city would be suicide seeing that the lack of soil, plant and animal life, or ground water has basically turned the deeper parts of the structure into a searing hot glass desert. Though many of the more secular scholars from all over the globe theorizes that at the center of these minerals there would be never before seen elements and precious stones with incredibly massive strengths and such unique properties that it would defy what people have known about the laws of nature.