Excavation may have stopped, but the long job of understanding what’s been found at Binchester Roman fort, near Bishop Auckland, is only just beginning. Ian Hamilton investigates

Dubbed The Pompeii of the North, Binchester Roman fort, along with its surrounding civilian settlement, has been the interest of archaeologists for centuries. It was probably built in the first century, originally from local timber, to house soldiers who guarded the crossing of the River Wear by Dere Street, the Roman road that connected York with Scotland. Much later, it was levelled and rebuilt in stone and at this point a commandant’s house and a large bath-house were added. A civilian population – probably the soldiers’ families – sprung up to the fort’s north and west.

Abandoned with the fall of the Roman Empire in the early fifth century, it was first discovered by archaeologists in 1878 when John Proud of Bishop Auckland and the Reverend Robert Eli Hooppell of Byers Green uncovered parts of the fort's defences along with fragments of the surrounding settlement. In 1937, archaeologist and army officer, Kenneth Steer uncovered more of the fort as part of his degree with Durham University.

But the work which led to the most recent activity headed by Dr David Mason began with a geological survey in 2004, which suggested a much bigger civilian settlement than had previously been thought. This led Dr Mason to ask Channel 4’s Time Team to spend three days in January, 2008 to continue excavations. The dig exposed more of the fort and three military mausolea, honouring dead soldiers.

The most recent dig, which ended in July and was staffed mostly by volunteers, was funded by Durham University, Durham County Council, Stanford University, English Heritage, Vinovium.org and the Roman Research Trust. It began in July 2009 and uncovered more trenches and artefacts both inside and outside the fort. An inscribed altar dedicated to the Roman Goddess, Fortune the Home-bringer, was among the finds.

With the recording and analysing work only just beginning, Dr Mason guides me through the commandant’s quarters before arriving at a 30m-long hole surrounded by metal fencing. In moments, we are tottering just feet above the best-preserved Roman bath-house in Britain.

To say it is well-preserved would be an understatement. Doorways and windows bricked up centuries ago are clearly visible. An archway with all but the top two feet intact reaches upwards, suggesting the true height of the building. Stone seating around the perimeter of one of the many heated rooms looks smooth and level. You can almost hear the raucous laughter of Roman centurions as they sound off about their officers. Instead, Dr Mason’s tells me what has been discovered over the last six years.

“Within the 300-year life of this building, the floor level didn’t change but, because they resurfaced and resurfaced [the adjacent] Dere Street, and because the buildings were knocked down and re-built many times by levelling off the debris and then putting the new building on top... you ended up with about eight or nine feet of archaeological deposits. So by the time you get to about 300AD, the level of Dere Street is about five feet higher than the level inside the building.

“One effect of that is that [Roman builders] had to construct a new entrance to the building. In the bath-house, they have cut out a window, put a little porch outside and put this little flight of steps going into it to make it into a doorway. And when the building was abandoned, they seem to have taken the top part of the structure away and used it as a big bin. It filled up fairly quickly and disappeared from sight.”

Dr Mason tells me that this concealed it from stone robbers, who were prevalent at the time.

“The stones from the Roman buildings at Binchester have been re-used in the surrounding area,” he says, “from nearby farm buildings to walls along the sides of the roads, to Escomb church. No doubt some was used to build Auckland Palace.

“[The fact that it was used as a rubbish bin] partly explains why it is so well preserved... Another reason is that this part of the field was never ploughed whereas the other side was. Had the ground not been ploughed, we would have had [even] more stones from the barracks left. Another reason why it is still here is that it is so substantially constructed.”

It is only when you look at the building carefully that you realise how innovative the Romans were. Doorways and windows have been blocked up and repositioned as they changed it to suit different purposes. Even plunge baths were added, along with a low stone bench in one of the 20 or so heated rooms.

One of many discoveries this year was a hypercaust (under-floor heating) that had been filled in. Dr Mason thinks that this means the original structure could have been up to 13 feet tall.

“There is no reason to think that the rest of the building is not equally well-preserved,” he adds, “because the main suite of bathing rooms is yet to be uncovered.”

In fact, he tells me that only about a quarter of the whole settlement has been uncovered, with geophysical surveys suggesting most of it still lies buried in all directions. I ask him why he has stopped now.

“It is an appropriate time to stop and get it all written up,” he says. “If we didn’t, what we have done would just be an act of vandalism.”

Doubtless this painstaking analysis over the next four years, will uncover yet more secrets about how this incredibly advanced civilisation lived.