Archaeology is being used as therapy for veterans and serving personnel who've struggled with injury or mental health, under the codename Operation Nightingale.
It's an unusual project that takes place on Salisbury Plain, somewhere many former or current servicemen or women will already be familiar with.
There the veterans and archaeologists are working together to search for the exceedingly rare Bluestone rocks, sourced only from the Preseli Hills in Wales, that are an integral part of Stonehenge and have yet to be discovered anywhere else.
Salisbury Plain is considered to be one of the most archaeologically significant landscapes in Britain, containing a vast array of historical sites, including settlements and burial grounds that are more than 6,000 years old, as well as remnants of military structures from the 20th century.
The veterans are working on Bowls Barrow, the oldest monument on Salisbury Plain which is also a scheduled monument – a nationally important archaeological site.
Richard Osgood, a senior archaeologist working on the site, says that having the opportunity to excavate it is rare and exciting.
A previous 19th-century archaeological dig in the area suggested sightings of Bluestone.
"So if it did have Bluestone in, that makes it incredibly important," Mr Osgood said.
Army veteran and volunteer archaeologist David Weiss Haynes said that it is an incredible opportunity to be "a part of history."
The possibility of discovering the elusive Bluestone is "tantalizing" said Mr Haynes.
"The idea that you just might find something that's of real historic significance. You know, if you're on that day, you'll recall it forever," he said.
Mr Haynes is 65 years old and, as a Cold War gunner, he spent a lot of time on Salisbury Plain with the Royal Artillery.
He suffered from an injury during his service and more recently has struggled with serious illness.
After recovering from back surgery and beating cancer, Mr Haynes is happy to be back on Salisbury Plain in a different role.
He sees the Defence Infrastructure Organisation-run Operation Nightingale as a form of "rebab" that gives him the opportunity to be active.
"It might seem really strange to get veterans back onto their training areas to dig holes and them to actually enjoy it," said Mr Osgood.
"But I think it's that human feeling of discovery and learning more about places that you've been quite familiar with in your day job.
"You're concentrating hard, you have to think about what you're doing, so you're maybe blocking out some of those memories that are more destructive about what you've experienced in the past," Mr Osgood added.
And, according to the senior archaeologist, veterans are well suited for the profession.
"There's links with the military from the very first start of archaeology. Lots of those people were military people," he explained.
"And it's looking at the landscape, appreciating topography, making discoveries, things that military are doing in their day jobs," he added.
Since Operation Nightingale began in 2011, the programme has helped more than 300 veterans and serving men and women.