Remains of Roman baths have been found beneath ordinary County Durham houses.

The remains, which are nearly 2000 years old, were discovered underneath back gardens in Chester-Le-Street.

The baths would have been used by Roman soldiers stationed at the fort of Concangis, a second-century settlement on the site of what is now Chester-Le-Street.

Records from the 19th century were used to estimate the location of the remains. Durham County Council archaeologist David Mason then worked with a team of local amateur archaeologists on a dig that uncovered traces of the bathhouse.

Due to the modern buildings occupying the site, the team couldn’t undertake a full dig. Instead they used a technique known as ‘keyhole archaeology’. The team dug ‘test holes’ in the back gardens so they could map the dimensions of the bathhouse.

In one garden, walls were soon discovered that turned out to be part of the bathhouse’s changing rooms. In the next door garden, the team found traces of the doorway and drainage system of the bathhouse’s ‘cold room’.

In the next garden along, the team unearthed remains of the ‘hot room’ along with evidence of its underfloor heating system.

The presence of the modern buildings meant the archaeologists couldn’t examine around half the site, but they were able to estimate what the bathhouse would have looked like from what they had discovered.

The bathhouse would have occupied forty square metres, with the structure boasting cavity walls and hypocaust (an early system of central heating) to conserve and distribute heat.

The bathhouse would have been built outside the walls of the fort because it was viewed as a fire risk. The buildings have been dated to around 150 AD. The Romans would have built the fort, during the reign of the emperor Hadrian, to protect Cade’s Road, which ran along the course of modern-day Front Street.

Mr Mason said, “In Roman baths, the soldiers would move along through cold rooms and hot rooms then apply oils which would be scraped off with a bronze blade to take the dirt and perspiration off.”

“It was a considerable building because there was a unit of 500 men and on each day around half of them would want a bath.”

Artefacts found during the dig show that the unit came from the Roman province of Gaul, which is roughly equivalent to modern-day France.

Mr Mason continued, “The military authorities would consider a bathhouse vital because it keeps their troops clean, improves levels of hygiene and therefore reduces the risk of disease, which would reduce their effectiveness as a fighting force.”

“We also have to think of bathhouses as a kind of leisure centre as well, where soldiers could relax.”

“Elsewhere there have been finds of chicken bones in the drains of bathhouses, so they served snacks. They may have boxed or done weights.”

“It was essentially a recreational centre.”