British archaeologists used thousands of aerial photos to reveal more than 2,700 unrecorded historic features of Hadrian’s Wall in northern England.
Among the new features identified by experts from the English Heritage were medieval sheep farms, ancient burial mounds and 19th Century lead mines.
The scientists used more than 30,500 pictures taken during the past 60 years as part of an English Heritage initiative to map and interpret England’s archaeological sites.
The project began in 2002, and includes a wide area on either side of the 73 mile length of the wall from the Solway Plain in Cumbria to Newcastle in the east.
Recorded features of Hadrian’s Wall, a World Heritage Site, include a World War II anti-aircraft gun battery near Cleadon, Tyneside, an Iron Age hillfort near Fourstones, Northumberland, and the abandoned medieval village of East Matfen.
"We need to remember that Hadrian's Wall is not an isolated monument set within a landscape devoid of any other history,” said David MacLeod of English Heritage's Aerial Survey and Investigation team.
"This region saw a tremendous amount of activity before the Romans arrived and after they left, traces and memories of which remain today,” he told BBC News.
"It will help us to understand and manage the rich heritage of human activity that has shaped this landscape, whether it is the remains of a Bronze Age farm or a 20th Century gun battery."