Archaeologists are excavating Cliff Park in Sunderland to learn more about its military history.
The site has been used for the defence of the River Wear and the nation since the Napoleonic Wars. It was the site of a Gun Battery during the two World Wars.
Convoys carried vital supplies down the North East coast to the Western Front during World War II. They came under frequent attack from submarines and aircraft. Artillery guns were mounted in Cliff Park to provide defence to the convoys and protect against invasion.
The guns were removed long ago but the concrete gun batteries have been turned into seating areas which are still in use.
Robin Daniels, from Tees Archaeology who are leading the dig, said: "A key role of this coast was trying to protect those convoys as well as trying to protect against invasion. But there's always a chance that there was earlier activity here, we have found three or four flints that may indicate prehistoric activity on the site."
The archaeological dig is organised by the Seascape project. The project aims to reveal the hidden heritage of the coast from the Tyne to the Tees. The excavations are funded by the National Lottery Heritage Fund.
Volunteers, interested in finding out more about their area's military history, have carried out much of the excavations.
Volunteer, Peter Holt, said: "My late father was based here, he operated the search lights during the Second World War, so I've always known there's been something here.
"Getting the chance to actually dig on the site was ideal."
Nicola Williamson grew up a few streets away in Roker, she said: "I wanted to volunteer because it's something local.
"I'm interested in military history, so for something like this to be happening on my doorstep, it's fantastic."
Whilst the site of the WWII guns was known, the location of WWI defences was not. Last year, volunteers carried out a geophysical survey which revealed two of the early gun positions and location of buildings.
The excavations have unearthed walls, previous floor levels, the remains of military vehicles, buttons, crockery and munitions. The excavations will help piece together how Cliff Park was used over the centuries.