The First World War broke out 100 years ago this summer — and although it's been extensively studied by historians, new information is still coming to light.
This week, a mock battlefield — complete with hundreds of metres of trenches — was discovered in the county of Hampshire, England. The trench systems were found in Gosport, on land owned by the Ministry of Defence. They are thought to have been used for training soldiers and planning strategy during the war.
The hidden trenches were first identified by Rob Harper, a conservation officer who noticed something odd while poring over an aerial photograph from 1951: a series of jagged lines off in one corner. And so began his investigation into their source.
"I found myself walking along a ditch and realised it was part of an elaborate trench system, hidden for all these years by bracken and gorse," Harper told the BBC. "I looked around and there were trenches everywhere."
The trenches cover an area of about 500 metres by 500 metres — making them one of the largest of the 14 known First World War training grounds in England, and an astonishing size to be kept hidden for so long.
The existence of these training trenches makes historical sense: Gosport had been used as a training ground during the war, and was a launch point for sending many soldiers out to sea.
"It is well-known that troops were stationed at nearby Browndown Camp but to date no historical records have emerged noting the practice trenches," David Hopkins, an archaeologist who is now surveying the site, told the French news agency AFP.
Archeaologists are currently in the process of mapping the trenches. And historians believe that their discovery will help explain how soldiers were trained before being sent off to war. In fact, they're now poring over old photographs and documents in an effort to learn more about that period of British history.
"We're identifying former drill halls, requisitioned factories and farm buildings, pill boxes, secret listening stations, acoustic mirrors, prisoner-of-war camps and gun emplacements — places that deserve to have the part they played in history made known," said Wayne Cocroft, English Heritage's expert on the First World War. "Buildings from Tudor, Georgian, Victorian times…these are all well documented. But the built history of the First World War in England is virtually a blank chapter."
For more pictures of what these trenches look like now, check out the gallery above.