Archaeologists have unearthed trenches dug across Northumberland moorland and used to train soldiers before they saw action in World War I.
Experts believe soldiers would have dug the trenches themselves
The army would have often dug trenches in the UK to help men learn how to eat, sleep and fight in the conditions in France and Flanders, they said.
The discovery was made by volunteers examining the Rothbury area.
Archaeologist Chris Burgess said it was an important reminder to the sacrifices made during the conflict.
He added: "It is a very exciting find, it is very important as well.
"People don't know they are here or what they were for.
"If we can let people know what happened here it helps people know what happened during the war itself."