ARCHAEOLOGISTS are to excavate historic burial mounds at Golden Cap before they are lost to the sea.

A team from the National Trust is holding a dig at the Bronze Age monument on the cliff top.

They will probe the three of the five earthworks – which are 4000 years old – amid fears that they will fall victim to landslips.

National Trust archaeologist Martin Papworth said: “These Bronze Age round barrows are important features of the landscape of Dorset and have a valuable story to tell but the archaeological information contained in these burial mounds can only be preserved through excavation and record.

“Total loss of the group through cliff collapse is expected in the next 50 years.

“The barrows are scheduled monuments and English Heritage has granted permission for the National Trust to excavate the most vulnerable parts of the barrow group.”

There are five burial mounds visible as earthworks on the summit of Golden Cap, which is the highest point of the coast path through Dorset.

The two furthest from the cliff will not be excavated this time but the three closest to the near vertical cliff must be archaeologically recorded as their destruction through landslip will take place in the near future.

The National Trust says that although erosion rates on the Dorset coast will have varied over the past 4000 years, it is thought the barrows would have been about two miles inland at the time they were built.

It says that is confirmed by the presence of some inland pollen types already found in an earlier dig.

In June 1992, a trench was excavated across the south-west barrow on the cliff top.

It was found that 30 per cent of the barrow had already been lost through coastal erosion. The mound was a cairn of chert rubble that sealed a charcoal deposit that gave a radiocarbon date of about 2000 BC.

The cairn had been re-profiled in about AD 1800 to create a signal station to warn against attack by Napoleonic forces.

The current excavation will be funded as part of the South West Coast Path Unlocking our Heritage Project largely financed by the European Agricultural Fund for European Development.

The work started on May 16 and will continue for three weeks.