WALKERS using stones to build landmark cairns could be placing ancient burial mounds at risk, a leading archaeologist has warned.

Ancient barrows and mounds have been part of the North York Moors landscape for as far back as the Bronze Age, when it was custom to bury people in graves built from piles of stones and located on hill tops or ridges along with artefacts such as pots or tools.

But the North York Moors National Park Authority’s archaeological consultant, Linda Smith, says modern-day cairns – often built by walkers to help mark a route or peak on the moors – could be placing them at risk.

They are often built from archaeological features on the moors, and moving the stones disturbs information within them, which could be used by archaeologists to gain information on life thousands of years ago.

She said that work is now underway under the park authority’s monument management scheme funded by Historic England, to ensure the monuments are protected.

In a blog on the park authority’s website Ms Smith described how many of the moors’ barrows were recognised as of national importance and were protected as scheduled monuments.

“The problem with building cairns today is that by using stones from existing archaeological features like barrows the information contained within them is disturbed, the clues that archaeologists use to build up a picture of what happened in the past are destroyed – how the structure was built and used, how it was developed for different burials, perhaps over several generations, or what objects were buried with the dead,” she said.

A group of park volunteers are now monitoring the condition of the burial mounds and carrying out remedial work to repair the worst of the damage.

A modern cairn was recently removed by the park’s apprentice team to reveal a stony, ancient burial mound beneath it. A second walkers’ cairn was taken down by volunteers at Raisdale Moor to protect archaeological remains underneath.

“We expect more burial mounds with walkers’ cairns to be tackled this year,” said Ms Smith.

“Beyond the obvious problems, making something more visible means that more visitors may be attracted to it, creating erosion. In some cases, a new cairn might obscure the monument altogether.”

Ms Smith said walkers on the moors were now being urged to help protect the landmarks.

She said: “Our heritage matters to all of us. Be careful not to disturb ruins and historic sites.”