One of Wales’ finest coastal heritage sites is under threat from cliff erosion and climate change.

Dinas Dinlle Coastal Fort in Gwynedd is a little known monument which dates back to late prehistoric times.

Based near Caenarfon, finds on the site suggest it was also occupied during the Roman period.

In the early 20th century it formed part of a golf course, whilst during the Second World War a pill box, seagull trench and observation post were built on the northern slopes to protect nearby RAF Llandwrog which is now Caernarfon airport.

Dinas Dinlle coastal fort is owned by the National Trust and is set on a hill of glacial drift sediments overlooking the sea and Caernarfonshire coastal plain.

Dinas Dinlle coastal fort is owned by the National Trust.

The fort is protected as a Scheduled Monument whilst the cliff face itself is a Site of Special Scientific Interest.

But some of the fort has been lost and some is still under threat.

Early maps suggest the fort was once entirely enclosed but today part of the western defences have been lost to the sea following thousands of years of coastal erosion.

Now, new research is being led by a team of archaeologists, surveyors, geographers and scientists from the European funded CHERISH - climate change and cultural heritage project.

Over the next four years the CHERISH team will carry out a number of studies to record and monitor the impact of the coastal erosion and also provide a greater understanding of the fort.

Louise Barker, a senior archaeologist on the CHERISH Project said: “This is one of the finest coastal heritage sites in north Wales, but is threatened by active erosion.

“Through our work we hope to gain a better understanding of when Dinas Dinlle was built and occupied, and how much has been lost to the sea.”

Initial work by the team has included new aerial photography from which it has been possible to create a 3D model of the monument and a new detailed survey to understand the site.

CHERISH has also funded a new geophysical survey to see beneath the soil which will be carried out by the Gwynedd Archaeological Trust.

The team hope to reconstruct as accurately as possible erosion rates over the past 150 years to give them an accurate view of how the site used to look.

Andy Godber from the National Trust said: “We are delighted to be part of this exciting project. Dinas Dinlle encapsulates the risk to our coastline from climate change.

“Being part of this innovative project allows us to learn more about the history of human occupation here while we still can.”