When Warwick Peirson stumbled on markings on a stone highlighted by snow little did he know it was to spark a passion which would span more than 30 years.
A winter walk with his young son on Ilkley Moor drew his attention to one of the hundreds of carved rocks which have occupied a swathe of West Yorkshire upland for thousands of years.
Efforts to find out more about the curious carvings – which date back to the Bronze Age – led to a quest he is still pursuing more than three decades later.
“I always knew about the stones but about 30 years ago I noticed a stone on Ilkley Moor and the carvings stood out with the snow,” said Mr Peirson, who lives in Menston.
“I went down to the museum in Ilkley to try to try to find out more and I realised there was very little information about them.”
The novice began his own survey mapping out the carved stones and has continued to study the artefacts ever since.
Mr Peirson, 68, said: “I realised that they must be one of the earliest forms of communication of writing, being about 4.000 years old. That fascinated me.
“I have found them addictive. I wrote a letter to the Ilkley Archaeology Group asking for information and wrote, PS, didn’t they think that all the stones should bear a government health warning because they were extremely addictive.”
So when a call was put out for volunteers to help with a survey to investigate the hundreds of carved stones on Rombalds Moor, Mr Peirson leapt at the opportunity.
He is among a group of more than 30 volunteers who are spending three years surveying the stones on the upland that lies between the River Wharfe and the River Aire – collectively known as Rombalds Moor.
Last year Pennine Prospects was awarded a Heritage Lottery Fund grant and South Pennine Leader funding to run the Watershed Landscape Project which covers a range of smaller projects, including Carved Stone Investigation Rombalds Moor.
Gavin Edwards, community archaeologist for the Watershed Landscape Project, said: “The survey on Rombalds Moor will be the most comprehensive undertaken in over two decades, and at the end of the 36 months, with the help of the volunteers, we will have gathered very valuable information.
“Prehistoric carvings are a unique and valuable part of our heritage, providing a direct link with the people who lived here over 5,000 years ago. Although stone is a long lasting medium, it is, nevertheless, subject to erosion by wind and rain and the destructive effects of vegetation.
“It is important to try and capture a detailed record of the carved stones and their surrounding landscape both for current studies and to guide conservation management, so we can protect them for future generations.
Existing records indicate that more than 300 carved panels lie on the moors between the rivers Wharfe and Aire.”
Ilkley Moor has the highest number of carved rocks but they are also to be found at Bingley Moor, Addingham, Baildon and Burley In Wharfedale.
Varying from simple marks to elaborate patterns, the carvings have baffled people for generations and it is still not clear why so many occupy Rombalds Moor.
“They do cluster in different parts of the country but why that should be, we do not yet understand,” said Mr Edwards. “Clearly Rombalds Moor was treated differently to everywhere else. It must have been a special landscape in which these were made but what made it special we just do not know.
“These are marks that were made by the same people who were working that landscape all those thousands of years ago and it is a really tangible connection we have with the past.”
The work is initially focusing on Ilkley Moor where people can learn the craft of recording the stones. Volunteers will record those which are already scheduled monuments, which protects them by law.
Mr Edwards said: “Although they are already known, what we are concerned about is whether they are deteriorating. The survey is to get a detailed record of them as they are today so that we can then see just how much weathering and damage is being caused to them in the future.”
It is hoped that the work will not only record the rate of deterioration but also throw light on what can be done to slow it down – hence preserving the historic stones for generations to come.
The survey will also photograph the carved rocks with a technique called photogrammetry, which creates three-dimensional images that will help researchers in their studies.