One of the Beamsley Beacon cairns that will be dismantled

Walkers are destroying priceless historic sites – to build hilltop cairns – and now a national park authority has pleaded to visitors to stop the custom to preserve structures that have been around since the Bronze Age.

Cairns have always been a contentious issue on Britain’s hills. For years, journalist and broadcaster Cameron McNeish has waged a war on what he sees as unnecessary edifices on Scotland’s wilderness peaks. Last year, many cairns were cleared from the summit of Ben Nevis and now the Yorkshire Dales are suffering from the cairn problem.

Rocks and stones are being removed from prehistoric sites by walkers making their own contribution to summit cairns. The practice is putting important relics at risk, including Bronze Age burial mounds.

Robert White, senior conservation officer for the Yorkshire Dales National Park Authority, said: “There are problems at a number of historically important sites within the national park, including Beamsley Beacon near Bolton Abbey.

“During the Bronze Age, some 4,500 years ago, a large stone mound was built there, probably to mark the burial place of a local chieftain and to act as a territorial boundary marker.

“Much of this cairn, which is now about 11m [36ft] in diameter, still survives but in recent years it has suffered a lot of disturbance due to people using stones from it to make modern cairns and wind breaks. Another smaller historic cairn lies further along the ridge at Old Pike and that has also lost some of its stones.

The prehistoric cairn in the centre with the trig point on its left and a modern cairn on its right

“The good views have always been appreciated. The name Beamsley Beacon, recorded in 1667, suggests it was used as part of a signalling system using fire. In 1804, during the Napoleonic wars, the beacon was refurbished and a guard house was constructed to shelter the beacon keeper. Unfortunately, the stone foundations of this building are also suffering from modern stone moving.

“We would urge walkers to resist the temptation to pick up stones and build cairns – wherever they are – because they can unwittingly damage ancient, historically-important sites like this stone mound.”

The Beamsley cairns and windbreaks will be removed by archaeologist Yvonne Luke and volunteers from the Yorkshire Dales authority. One windbreak will be left in place.

An archaeological survey of the hilltop has been carried out and Mr White and his team are now appealing for old photographs of the site to help them build up a picture of what it was like in the past.

The authority has put a temporary poster on the nearby trig point pillar urging people not to build cairns and explaining why. A permanent interpretation panel is planned for the site eventually.

Anyone with information or photographs that can help Mr White is asked to contact him on 0300 456 0030.