A mysterious cave with many, many nature-made routes in it. Most people don't try to explore the cave, since many have not been able to get out and died of many reasons, mostly starvation and insanity. Many have also gone into the cave and are said to have never came back without a trace.There are also know to be kishin hiding in there because of the many routes, which gives them easy prey. There is a legend that some routes take you to different dimensions,and another about the ghosts of lost explorers haunting the cave, but those are just legends... right?