Thousands of years ago our Neolithic forebears were hunting wild game with flint arrows in the hills overlooking what is now Ballymena. Now they’re still making their presence felt, delaying a road dualling scheme that was aimed at easing congestion between the town and the M2.

The A26 Ballee Road East to M2 Ballymena bypass dualling scheme was due to be completed by the end of this month. But bad weather and the discovery of rare Neolithic remains have pushed that deadline back to late summer, costing tens of thousands of pounds.

The plan was to dig through a hill and use the material to build embankments elsewhere in the route. But when the topsoil was being stripped away, archaeologists uncovered a series of historical hotspots where more investigations needed to be carried out.

Many of the hotspots found by Archaeological Development Services Ltd during the topsoil stripping were isolated pits which contained burnt bone and Neolithic pottery.

But the big find was a rare Neolithic ring fort unearthed at just the point where the cutting was to be excavated — one of just four found so far in Ireland. This was investigated by 20 archaeologists for eight weeks.

The fort’s remains lie two miles southeast of Ballymena, overlooking the Larne Road roundabout to the north, and was set on the north edge of a drumlin 60m above sea level.

The enclosure was more or less circular, between 40m and 45m in diameter, with two entrances or causeways. One spanned a gap of 25m around the west side of the enclosure, while the other lay towards the south end measuring 3m wide.

Inside the enclosure is what appears to be a series of structures, including rectangular and circular shapes with pits and hearths. Archaeologists have discovered flint chippings, small blades and a leaf-shaped arrowhead.

DRD said excavation of the cutting and removal of the material to build embankments elsewhere on the site would have been completed during the 18-week period from mid-June to late October, if it hadn’t been for the discovery.

Wintry weather also held the work up and the cutting won’t now be excavated until spring’s drier conditions.

A DRD spokesman said: “Following completion of the cutting and construction of embankments it is hoped that the remainder of the road construction will be completed at a fast pace to allow the road to be opened to traffic in late summer 2010.”