Some of Wales' most iconic ancient heritage sites are in danger of being eroded by the growing numbers of visitors who are tracking them down.

Earlier this week the Pembrokeshire Coast National Park Authority's staff and volunteers carried out urgent repair work to reduce the impact of two bronze age cairns, believed to be located in the Preseli mountains.

But over the past twelve months, the National Park has witnessed a growing number of incidents involving historic sites and landmarks which have been damaged, either intentionally or as a result of general wear and tear. 

These include Tenby Castle and the Pembroke town walls while pagan rituals have seen the burning of land around ancient neolithic sites such as Carn Ffoi and Bedd Morris, which are both located near Newport.

The National Wales: Tenby castle wall daubed by graffitiTenby castle wall daubed by graffiti

As a result, the Heritage Watch Scheme was introduced, enabling Pembrokeshire’s 11,000 archaeological sites and ancient historical landmarks to be addressed and monitored.

Temporary fire pits have been installed at sites of pagan significance, while the bronze cairns have been re-created into 3D models with the help of a drone.

“Over time, visitors have been reshaping the form of the cairns which makes it more difficult to identify their original form,” said Tomos Jones, of the Pembrokeshire Coast National Park’s historical sites department.

“Obvious disturbance to the sites can also encourage others to add their mark, thus making the problem worse.

"Due to the ongoing nature of this issue, it’s not possible to reconsolidate exactly as they would have been prior to disturbance.”

The National Wales: Pembroke town walls daubed with graffitiPembroke town walls daubed with graffiti

The National Park has utilised its drone to build 3D models of the cairns both before and after the consolidation work was carried out. These will subsequently be used to compare with future surveys and help identify the extent of any future disturbance.

Meanwhile if anyone is aware of any form of heritage crime, they are asked to report it using #OpHeritageCymru.