dark creepy glowing phosphorescent smiling face on hanging stone in cave

abandoned adit byaki cave cavern corridor creepy danger dark decay decoration deep dungeon exploration face flooded formation funny geology ghost glowing grove halloween hazard horror illuminated inside interior jack lantern light limestone long mine miner mineralogy minerals mining mold mould must mustiness mystery natural nature nickel old ore passage phosphorescent quarry region rock scary science smile smiling speleology spooky stone structure symbol tula tunnel underground water zombie