What is thought could be Helston's earliest settlement dating back more than 3,000 years looks likely to be built over by a major new housing development.

Two Bronze Age roundhouses dating back to around 1,000 BC or earlier have been uncovered on farmland adjoining Bulwark Road, along with an Iron Age burial site and ditches, plus a small industrial area.

The discovery at Higher Nansloe Farm has raised questions locally over the future of the project by Coastline Housing to build 75 affordable homes, but the authority indicated this week that there was no change to the plans.

A spokesperson said: "As is usual on sites like this, all of the findings will be fully recorded and certain artefacts will be taken off site for safe keeping before further development work takes place."

Archaeologists from the Exeter branch of Cotswolds Archaeology have been working on the site for the last week, but are due to wrap up their involvement today.

Investigative trenches dug last November, following an initial radar survey, suggested that there could be some areas of historical interest, which has led to the excavation work over the last week.

The extent of the discovery though has been described as "completely unexpected," particularly in relation to the houses and graves, which are just over the hedge from Nansloe Academy, the primary school immediately neighbouring the site.

It is now considered "extremely likely" that neighbouring fields could also be hiding more historical secrets underneath the soil, with further round houses particularly likely.

A spokesperson for Coastline said: "The archaeologists have found significantly more features along the eastern site boundary than were anticipated from the radar survey results. The radar survey indicated that there would be no remains in this area, but the archaeologists have discovered two probable roundhouses, a possible prehistoric stone burial feature, together with further ditches, pits and postholes."

The site is currently surrounded by high metal security fencing and not accessible to the public, although neighbouring school pupils might be getting an exclusive look round.

Coastline said its contractor would be arranging an accompanied site visit for the pupils to view the archaeological features.

Charles Field, headteacher of Nansloe Academy, said he was excited by the discovery and the opportunities it could present for pupils to see history brought to life.

Mr Field said: "I just think it's really exciting to be on the site of what could possibly be the first settlement in Helston.

"It would be fantastic to involve our children in this rich discovery and are very excited about the opportunity."

Houses in the British Bronze Age were usually circular with either a dry stone wall or made from wattle and daub - strips of wood woven together (the wattle) that were then daubed with a stick mixture of clay, wet soil, sand, straw and animal dung.

Previously the nearest examples of similar roundhouses could be found in west Penwith, at Bodrifty, where there are more than 20 Bronze Age monuments and an Iron Age village.

The discovery in Helston suggests that settlers chose the spot at Higher Nansloe Farm for its raised position, overlooking the sea at Loe Bar.

The development is already the subject of a legal challenge attempting to bring about a halt to the work, following planning permission being granted by Cornwall Council.

Coastline said it was unable to comment any further on this matter for legal reasons.