Far more than just a faint echo of the past, Ireland's fairy forts are still vibrantly alive.

The traditions connected to them are so powerful that, even today, people rarely interfere with Irish fairy forts or fairy trees. They aren't built on; roads curve around them; farmers don't plough over them

The most numerous ancient remains in Ireland today, numbering up to 50,000 or more, these enigmatic mounds and grassy banks seem to call out to us from an earlier time. So, what are they, who built them and what were they for? And how have so many survived for so long?

With evocative photographs by Richard Mills, master folklorist Jo Kerrigan explores the origins of these mysterious circular structures: the stories and legends, the history and archaeology, the living traditions and practices connected to them. And reminds us of the dangers of disturbing the ancient spirits dwelling beneath.