The Edge has a long history as a mining area since the Romans, and maybe earlier peoples, first started extracting copper ore; there are numerous mine shafts and tunnels in the area. A caving club gives guided tours. Next to the National Trust car park is The Wizard, currently a restaurant. And near it is the Wizard Wood. So the area has associations with wizards and witches and mystical goings-on. Allegedly witches used to meet there every halloween to perform strange rituals and dance about naked. So lots of people started to arrive to look for the witches. Now wandering about in woods full of old mineshafts and cliffs at night is not a good idea, especially if you've got tanked-up beforehand, so eventually the police had to fend off visitors for their own protection. Fortunately it's all died-down these days.