More than 3,500 new archaeological sites have been discovered in the New Forest National Park, thanks to high-tech laser mapping technology.
Using images beamed back by lasers from aircraft, researchers have found previously unrecorded sites and monuments.
These include an Iron Age fort, Bronze Age burial mounds and a Second World War decoy-bombing site.
On two occasions, in 2011 and 2012, archaeologists used a plane to fire harmless laser beams into the ground to build a 3D map of the surface. The Light Detection and Ranging technology (LiDAR) can penetrate the tree canopy, revealing features that cannot be seen by other means.
The entire National Park and its surrounding communities – an area the size of 92,000 hectares or 350 square miles – was surveyed by LiDAR.
To the north of the New Forest the team found seven previously unrecorded Bronze Age burial mounds, dating to around 2,000 BC.
Lawrence Shaw, the heritage mapping and data officer for the New Forest National Park Authority, told historyextra the area might have been used for a family burial.
The team also discovered an Iron Age hill fort with a system of banks and ditches.
The fort, most likely used for inhabitants or to protect livestock, could be interpreted as what archeologists describe as a banjo enclosure, due to its elongated entrance seen to the west, which gives it an appearance of a banjo.
“This is fantastic,” said Shaw. “It’s a great example of what you can see below the trees.
“No fort in the forest looks anything like it.”
The research has also shed new light on two Bronze Age barrows on Beaulieu Heath, damaged in the 19th century by a local rifle club as they built a target range. The laser mapping shows one of the damaged barrows to be severely misshapen.
“This is my favourite site in the forest,” said Shaw. “We went out to survey it after looking at the laser mapping, and we now know that between 1869 and 1897 someone modified one of the barrows to turn it into a range for rifle practice.”
The team was also able to accurately map a Second World War decoy-bombing site, 800 metres west of the barrows.
There, the military would have lit fires to confuse enemy bombers flying overhead into thinking they had successfully bombed the site, or that they were flying over a bombed location such as Bournemouth or Southampton.
Over the next seven years, archaeologists will carry out ground verification on the 3,500 new archaeological sites and monuments, and work to preserve them.
“This has improved our knowledge of the history and archaeology of the New Forest exponentially,” said Shaw.
“There is so much more for us to be looking at and we are far from having the whole picture, but as a way of moving forward it’s really exciting.”
Dr Bob Johnston, a University of Sheffield historian specialising in Bronze Age Britain and Ireland, told historyextra: “Archaeologists are using Lidar to transform our understanding of the historic landscape.
“It is especially valuable in areas such as the New Forest, where tree-cover makes other forms of archaeological survey very difficult.
“It is terrific that this project is discovering lost Bronze Age barrows.
“So many of our barrows have been lost through ploughing and other forms of development. Yet here in the New Forest they survive, intact and hidden beneath the trees.”
The data was acquired as part of two projects run by the New Forest National Park Authority – a Heritage Mapping Project, funded through Europe’s largest Higher Level Stewardship scheme with the Forestry Commission and Verderers, and the New Forest Remembers Second World War project, funded through the Heritage Lottery Fund.