Work has started to excavate three Bronze Age burial mounds on Golden Cap in Dorset (England). The 4,000-year-old mounds are at risk from coastal erosion and are being excavated by the National Trust before they are lost to the sea. There are five burial mounds - each about 15m (49ft) in diameter - visible on the summit of Golden Cap, the highest point of the coast path through Dorset at 191m (626ft) above sea level. It is not known exactly how high each mound is because they have been covered by sand blown in from the cliff edge. Each one currently stands at about 1m (3ft) high.    
     In 1800 half of the south-west barrow was dug into to create a signal station to warn against attack by Napoleonic forces during the French invasion. In June 1992 a trench was excavated across that barrow, which dates to about 2000 BCE. It was found that 30% of this mound had already been lost through coastal erosion. Preliminary excavation work was carried out on the mounds in May 2009, while the two mounds furthest from the cliff will not be excavated this year. All five burial mounds are expected to be lost through cliff collapses in the next 50 years and it is thought the mounds would have been about two miles inland at the time they were built.
     Martin Papworth, a National Trust archaeologist, 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." Mr Papworth added: "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." The current excavation work is expected to last until 3 June.

Edited from BBC News (18 May 2011)