The Crystal Caverns
No one who has journeyed to the Crystal Caverns will ever forget the beauty of the myriad crystals glittering in the light brought down by adventuring parties, nor will they forget the things that they see and here there, snippets of past conversations and even glimpses of people or events that took place long ago. Some think that the Crystal Caverns are a place of wonder, whilst others believe they are a place to be feared and treated with superstition.
Like most parts of the Middle Underdark and the Underdark in general, the Crystal Caverns are for the most part pitch black, but when any source of light is brought within this particular cave and tunnel network, the light is reflected and amplified into dazzling brilliance by the crystals that cover almost every surface in this region. The crystals that give their name to this area are a variety of crystal only found in this cave network, known as Kinitiki, or sometimes more colloquially as Deep Stones, which are flawless, clear gemstones that are variously found in lilac, purple, pink and blue colours. The Kinitiki gemstones, as well as making this region outstanding beautiful if light is brought into the cave network, also make the region hard to travel through, as their sharp points and edges quickly puncture and tear through any shoes or boots travellers might be wearing, shred flesh and hide and their mirror sheen polished flat surfaces are also treacherously slippery. To make matter worse, in some areas, the crystals have formed into hollow columns that act as vents, drawing up clouds of noxious gas from deep below even the Underdark, which shrouds the areas in choking fumes. Whilst most the majority of the Crystal Caverns are located in the south east of the Middle Underdark, the numerous tunnels do lead all the way around and have been known to connect to an area of Kinitiki stone caverns in the west of the Middle Underdark, leading most people to believe that they are one continuous network.
The Kinitiki gemstones that make up the caverns make navigation through the area notoriously difficult, not only because they reflect any light in such a confusing dazzling way that it can easily disorientated people, but they give the landscape an oddly featureless, repetitive feel, making even the most seasoned of Underdark travellers struggle to remember which way they have come. The gemstones themselves also disrupt the working of any compasses brought down into the Crystal Caves, and have even been known to tamper with arcane navigational devices as well.
The Glittering GhostsWhat makes people most wary and superstitious of the Crystal Caverns is a phenomenon reported by those who have travelled there and survived the return journey that is most commonly called the Glittering Ghosts. This phenomenon is said to manifest itself at first as the whisper of voices in the minds of traveller, voices from their past, most often close friends, family or others who have significantly impacted their lives. From there, people claim that they start to glimpse ethereal versions of these people, who glitter with the same brilliance as the Kinitiki gemstones that make up the caverns, and some people say that these projections are so strong and real that they are able to have conversations with them. The phenomenon of the Crystal Caverns leads some people to deliberately travel there, believing that it is a place they can commune with those who have passed on, but many people instead believe that it is a vile trick, designed to draw people deeper into the cavern network so that they get lost and perish. Arcanologists and scholars from both the surface world and the Underdark, who have studied samples of the Kinitiki gemstones brought back from the caverns have tried to dismiss the stories of the Glittering Ghosts, claiming that the phenomena is instead related to a curious property of the Kinitiki stones that causes it to resonated at the exact same frequency as the electrical signals of most humanoid brains. This property of the Kinitiki is they believe cause hallucinations which manifest as the strange sights or beings encountered by those who have travelled there, but speak to anyone who has been to the Crystal Caverns, and those that managed to escape with their minds in tact will tell you what they encountered was no illusion.
Fauna & Flora
The Crystal Caverns are one of the most inhospitable places for life anywhere within the Underdark, save for the lava fields of the Deep Underdark. Unlike the rugged rock surfaces of the rest of the subterranean expanse, the crystal walls of the cavern system provide very little purchase for mosses, lichens or fungi to cling onto, meaning that the standard array of flora able to survive in the Underdark is rare in this area. However, life is still able to survive here, thanks to the presence of the crystal gas vents, which belch out a noxious mix of gases dredged up from deep below even the levels of the Underdark. Though these gas vents seem at first glance as inhospitable as the rest of the Crystal Caverns, an ecosystem has been formed around microscopic flying organisms. These organisms, known as Anemos Plankton, are able to feed off of nutrients brought up in the gases, which form the foundation of a food chain in which larger organisms, found nowhere else on the Material Plane of Kelbonnar.
The Kinitiki stones themselves are the main natural resource in the area and expeditions are regularly sent down to the Crystal Caverns to collect the stones, which fetch a high price in markets both on the surface and in the Underdark of Kelbonnar, both for their beauty and uniqueness and the fact that the stones are theorised to hold the key to unlocking extra sensory powers and unnatural mental abilities.