Leominster'S biggest-ever archaeological excavation uncovered important clues about the town's long history.

The extensive dig, covering half an acre of the Focus DIY development site at Mill Street, revealed that Leominster was a hive of industry from a very early period.

A large volume of iron working slag found below ground could date from pre-Roman times. Blacksmiths may have toiled in forges at the site for centuries.

Before the dig began underground scanning equipment revealed 'hot spots'.

"We were very excited by what we saw," said archaeology team leader Huw Sherlock. "The slag really stood out in red on the screen. When we excavated the area we found the huge dump of iron waste which must be the remains of a very large-scale iron working enterprise.

"We are awaiting the results of dating tests and, for the time being, our best guess that it could be pre Roman. The area seems to have been the focus of an iron-working industry for many centuries."

A number of other trades, including flax processing and tanning, were known to have been carried on in ancient times in the area which may have been the town's first 'industrial estate'.

The major dig provided a "fascinating glimpse" into Leominster's past, said Huw of Westhope, the director of Archenfield Archaeology.

"We found the remains of substantial medieval buildings close to the River Kenwater and just outside the limits of the Priory precinct," said Huw.

"A series of large ditches were found to contain well-preserved stakes and a fence line consisting of wattle hurdles carefully placed in the base of the ditch. It is thought the ditches may have been part of a fish-farming or fish-trapping system.

"We found a causeway made of large pieces of slag and unglazed medieval floor tiles bisected the site from north to south. Tantalisingly, the causeway was heading in the direction of the recently discovered possible 'rotunda' on the north side of the Priory."

Footings of the rotunda, or round church, thought to date from Saxon times, were shown to exist beneath a car park during another project, a ground penetrating radar scan carried out for the Friends of Leominster Priory. The major find was exclusively reported by the Hereford Times earlier this month.

The Mill Street diggers also uncovered a large quantity of glazed medieval roof tile, a medieval coin, pieces of lead flashing and several large iron keys .

The finds are now being analysed by experts but there is no doubt in Huw Sherlock's mind that the dig uncovered some important pieces of Leominster's historical 'jigsaw'.

The positive attitude of the landowner/developer was crucial, said Huw. "Frank H Dale Ltd recognised the sensitive archaeological background of the site and was co-operative in ensuring the area affected by the new development was fully recorded," he said.