Hidden Roman ruins discovered by archaeologists using lidar in lockdown

Lidar uses very small lasers to create an accurate 3D image of any surroundings by measuring the distance between the sensor and a target object. It is currently used as one of the key technologies that allow driverless cars to understand and navigate through their environment while avoiding hazards.

It has now been used to find around 30 prehistoric or Roman large embanked settlement enclosures; around 20 prehistoric burial mounds, as well as the remains of hundreds of medieval farms, field systems and quarries.

Further discoveries in the coming weeks are expected from the University of Exeter team responsible for these latest revelations.

In 2018, the same technique was used in Guatemala to discover over 60,000 previously unknown Mayan structures, including pyramids, palaces and causeways.

Lidar is used during aerial surveys to produce highly detailed topographical maps. Modern vegetation and buildings can also be removed from the data, allowing archaeologists to look at the shape of the land surface to find the remains of archaeological earthworks buried below.

The data is being systematically examined and cross-referenced with records of known archaeology and historic maps, meaning the total of new discoveries regularly changes.

Team leader Dr Chris Smart said: “The South West arguably has the most comprehensive lidar data yet available in the UK and we are using this to map as much of the historic environment as possible.

“The project’s current focus is the Tamar Valley, but this has been extended to include a broad swathe of land between Bodmin Moor and Dartmoor, Plymouth and Barnstaple – about 4,000sq/km in all.

“This is the first major systematic analysis of lidar data from the Tamar Valley westwards and builds upon training workshops we ran earlier in the year.

“Ordinarily, we would now be out in the field surveying archaeological sites with groups of volunteers, or preparing for our community excavations, but this is all now on hold.

“I knew there would be enthusiasm within our volunteer group to continue working during lockdown – one even suggested temporarily rebranding our project ‘Lockdown Landscapes’ – but I don’t think they realised how many new discoveries they would make.”

When the worst of the pandemic is over, the team intends to undertake geophysical surveys at a number of the newly identified sites as part of the 'Understanding Landscapes' project.