The remains of a Roman roundhouse, thought to date back to the second century, were discovered as United Utilities were working on a new pipeline project, on grazing land near Garstang Road East.

The amazing find was unearthed five weeks ago as work on a £10m sewer improvement scheme began. As is the case with any large scheme, an archaeologist was present on-site in case anything of historic interest appeared. Within hours of the workmen moving in, it became clear that a significant discovery had been made.

Alison Plummer, from the Lancaster office of Oxford Archaeology, which works with United Utilities, said: "As the topsoil was stripped away, we realised we were looking at something very exciting and rare.

Dated

"Finds like this are very rare in Lancashire, and especially rare in this area, there are only two other Roman roundhouses that we know of in the county – one outside Lancaster and one near Lathom.

"Our team of 10 archaeologists are now working at the football pitch-sized site, painstakingly uncovering and documenting what remains of the Romano-British roundhouse which is around 10m diameter."

A small amount of black burnished ware pottery, thought to date from around the second century, has been found which has helped experts date the roundhouse.

The remains of the house, which the team believe would have been a dwelling house, include an outside drainage gulley, holes for the timber support posts, some cobbles and a storage pit.

The archaeological team believe they have also discovered signs of a further roundhouse a few metres away, suggesting this could have been the site of an early settlement.

Local people are invited to see the site for themselves tomorrow as part of an open day before the site is covered over once more.

Poulton-based archaeologist Pascal Eloy said: "This is such an important find and it really re-writes Poulton's history.

"Previously there was a big gap in history in this area, so it is really exciting to have this link with the Romans here."

The site will be open between 11am and 3pm for members of the public to see the discoveries.

The team is appealing to people to keep away at other times in case the site is disturbed.

Archaeologists will be on-site for the next two weeks documenting every detail of their finds and taking photographs which will eventually form the basis of an information archive.