As a child, Mary McKeown played hide and seek amongst the Beaghmore Stone Circles in her native County Tyrone. It's a mysterious, mystical site with seven circles, ten rows of stones and twelve cairns, all seemingly carefully aligned. They were found by turf cutters in the 1930s, excavated in the 1960s and carbon dated back to the early Bronze Age. There are many theories about what they were used for - perhaps a burial site, a place for harvest ceremonies, or some sort of lunar or solar calendar. The belief that the stones were connected to celestial events prompted Mary, now working as a tourism officer, to bid for Dark Sky status for Davagh Forest, a short distance away. It's one of the few areas in Northern Ireland unaffected by light pollution. In Irish, 'davagh' means cauldron – the site sits in a natural bowl in the forest protecting it from artificial light from surrounding towns and villages. Davagh became the world's 77th Dark Sky park and the first in Northern Ireland. Mary and her colleagues were also successful in getting funding to build an observatory. Resident astronomer, Barry Lynn, operates a telescope through a retractable roof and projects images of the skies on screens around the park. He says he was first attracted to the area by his interest in archaeoastronomy, the study of how past cultures viewed the skies. He says its fascinating to think that centuries ago, people watched the same moon, sun and stars as we do today. Back at the Beaghmore Stones, Helen is persuaded to join Mary for a barefoot walk inside the circles. Some believe that the 'energy' of the landscape promotes a sense of mental well being. Helen remains unconvinced about this, but enjoys recapturing childhood memories. Produced by Kathleen Carragher