Of the three perilous zones, the grotto Yen Xu mentioned was one of them. East of the Deer Mountain Range, there was a small hill with nothing outstanding other than the fact the grass was always damp every second of every minute of every day despite the season and day.
Due to the weird phenomena, most thought there was something mysterious, possibly some natural treasure lurking in the area that contributed to the phenomena.
However, after countless years of exploration, nothing out of the ordinary other than the drought-resistant grass that was even immune to a certain degree to various fires, nothing special was ever found.