The excavations, which were carried out between April 19 and May 4 2008, have uncovered tools dating back to the Mesolithic period (8000 – 4000 BC) when the area may have been wooded and people were hunting animals, foraging for nuts and berries and making their camps in the area.

Finds include a flint arrowhead dating to the Mesolothic period together with several fragments dating to the Bronze Age, when the mound was built, 2000 to 3000 years ago.

Perilously close to the cliff edge at Peacehaven, the Scheduled Ancient Monument is fast becoming too dangerous to investigate because of coastal erosion.

Archaeologists expect the mound to fall into the sea completely in the next 25 years and English Heritage and the landowner agreed to its excavation by Brighton and Hove Archaeological Society and the Mid Sussex Field Archaeological Team to record as much information as possible.

The mound also produced pottery and clay pipes dating from the 1700-1800s, which could point to earlier antiquarian robbing of the mound. It was also used for defence purposes when soldiers dug their slit trenches through it during World War II as part of their defence of the coastline and a nearby radar station (now demolished).

Project leader Susan Birks said: "This mound has a complicated history spanning several thousand years BC right up to World War II. It's a complex story that will need careful unravelling, but we have gathered enough information to tell us its age and something about the people who built it.”

Once the excavations have been completed, the barrow will be reinstated as it was, and the results will be collated into a report for dissemination to archaeological and local societies, as well as East Sussex County Council and English Heritage. Any finds will be donated to Brighton and Hove Museum.