David Etheridge noticed a concrete structure at the foot of the cliffs at Saunton Sands while on holiday in Devon.
He set off to explore and realized it was part of a ruined bunker guarding the beach.
Around 10,000 American soldiers used beaches, estuaries, and sand dunes in North Devon to prepare for the D-Day landings.
The event saw Allied troops invade German-occupied France on June 6, 1944, in the largest seaborne invasion in history.
Now, Devon County Council has confirmed the site will be added to their Historic Environment Record, along with David’s photographs.
“I knew Saunton Sands was used by the U.S. military in preparation for D-Day, and instantly suspected it was part of their training ground,” David said.
“I wanted to know more, so when I got back, I looked it up, but to my surprise found nothing, so I contacted the local archaeologists.
“If I hadn’t spotted this, in a few years it would have fallen into the sea and no-one would have been any the wiser, I’m very pleased I found it.
“The Normandy landings continue to be an important part of our national consciousness, and this small structure played a significant role in ensuring D-Day was a success.”
David is the program manager for Strode College’s History, Heritage & Archaeology Foundation Degree.
Epoch Times contributed to this report.