The Vaults of Malta

"An endless cavern spread out into the dark, hazy horizon. Its ceiling was nearly half a kilometer from the ground. A large lake flowed and simmered at the bottom of the cave, filled with crystal clear water. Several islands and pillars of rock jutted out of the lake. Water poured in from above, with thousands of tiny waterfalls cascading from the walls and roof. Below them little travertine terraces of limestone formed a series of small pools and steps that gently descended into the waters. 
Small gems glittered on the walls and ceiling of the cavern, each emitting a tiny bit of light. From here the might as well have been stars in the night, for only the beauty of the galaxies and nebulae could describe how they glimmered from beyond the sea of misty clouds. 
As beautiful as they were, it was not them that drew Raihan's attention. Massive hexagonal stalactites and stalagmites of violet crystal resembling amethysts emitted a purple light, illuminating the dark haze in a brilliant purple. The stuck out from the lakebed below, emerged from the hazy clouds above, and grew into little stone pillars that hung from the walls. These were no ordinary gems, however. Their sheer size dwarfed any natural gems found on Earth. Some of these massive crystals were the size of skyscrapers. Each was a hundred metric tons of raw rock, and there were hundreds, if not thousands of them. One could have built a whole city from crystal, and had some to spare. In fact, that seemed to have been what happened.
All across the walls various structures made of yellow limestone and dusky rock had been carved into the face of the caves. Pillars and arches stuck out from ruined pavilions and collapse roofs. Dozens of ruins littered the surface of the caverns as well. spires and domes jutted into the dim violet horizon, and bridges wove their way across the waters and stitched the many little islands together." 
-why did I write this on here instead of in my book? idk. (note to self, delete this and write an actual description later)