An unusual night time experiment took place at the weekend in hills spanning the England-Wales border. The Hilltop Glow event saw up to 200 volunteers stand on the summit of ten prehistoric hillforts in an effort to establish whether the original Iron Age inhabitants communicated with beacons.

The Clwydian Range of northeast Wales and nearby Llantysilio Mountain are popular with modern hillwalkers, but their human occupation dates back thousands of years and the area is known for its extensive network of hill forts, ancient sites that occupy prominent summits across Denbighshire, Flintshire and adjacent parts of Cheshire. Hillforts used in Saturday's event included one near Corwen in south Denbighshire, four on the Clwydian Range, one on the Wirral and four on the Cheshire Sandstone Ridge.

The experiment on Saturday 19th was designed to test lines of sight between the sites.

'Because we do not have any written sources from this time, only very brief accounts by the Romans some time after the invasion of Britain, we do not know a lot about the hillforts.' explains Erin Robinson of the Heather and Hillforts Landscape Partnership.

'From excavation we know that most date to the Iron Age, around 2500 years ago. However there is still quite a big mystery about what they were used for, whether they were used by the same tribe or by enemies protecting their patch, or if they all had different uses, such as trading places or farms. In the area we were looking at there are around forty hillforts in total, which makes it incredibly important. We chose ten hillforts to see if we could make connections between them, to see if they could have been of one community.'

'People from all over north east Wales, the Wirral and Cheshire banded together to help us make the hillforts 'glow', allowing them to be seen from other hillforts up to 40km away, where their friends and colleagues were watching and signalling back.'

'Not only did we make great connections, but we also felt really close together as when you saw a light signalling from another hillfort [it] made us all feel as one - as though we belonged together. Many people commented about the ancient feet that had trodden this path before them and that they could almost imagine what it would have been like in the Iron Age.'

Local volunteers were joined by representatives of several organisations including Chester University, RSPB, Flintshire and Denbighshire Councils' Countryside Services and English Heritage. The event was jointly organised by the Heather and Hillforts (north east Wales) and the Habitats and Hillforts (Cheshire) Landscape Partnership Schemes, both funded by the Heritage Lottery Fund.