What is the mystery of Pendle Hill?

Could you please elaborate on the enigmatic nature of Pendle Hill? What are the legends and tales surrounding this intriguing locale? Is there any historical significance attached to it? And, what are some of the unexplained phenomena or occurrences that have been associated with Pendle Hill, adding to its allure and mystery? I'm eager to understand the full breadth of its mystery, if you would be so kind as to share your insights.