Possibly an ornamental garden area formed from what looks to be a quarried out ravine with small pond-reservoir above a small watefall, now overgrown and ruinous.
There are small footpaths and one larger, all overgrown and only accessible by a small loop, away from the main, modern paths of the area.
Disambiguation: There is another Fairy Glen on the Sprodley Brook at Appley Bridge that is better-known.
Historic monuments near Fairy Glen Wigan