The secrets of the land

The tiny infants were discovered during construction of the M6 motorway in an unconsecrated graveyard, or cillín, used between the 15th and 18th centuries.

Cillín were the final resting place for those of an unknown religion, criminals, suicides, women who died in childbirth, people with an intellectual disability, unbaptised babies destined for limbo – a place between heaven and hell – and others whom the church deemed could not be buried in consecrated ground.

"The excavation of such burials makes us think of the immense tragedy and sadness associated with the loss of a child and their place of burial," National Roads Authority (NRA) archaeologist Orlaith Egan says.

"They also remind us of the high infant mortality rate that was part of everyday life in the not-so-distant past."

In use between the 13th and 20th centuries, there are thousands of cillín sites across the country, many secret and unrecorded. Some 248 burials were excavated at one, at Tonybaun in Mayo. They are among thousands of discoveries made during construction of the national road network between 2000 and 2010, many of which will be showcased at a major conference in Dublin next week.

They include fish traps or baskets almost 10,000 years old, preserved in ancient bogs. The earliest wheel found in Ireland emerged on the route of the N5 between Dromod and Roosky, while a deserted medieval village was found at Mullamast on the M9, near Athy in Kildare.

"Some of these settlements were huge," NRA chief archaeologist Ronan Swan says. "We have found house plots, streets and roads. It could have accommodated more than 100 people and was in place for a couple of hundred years.

"If the roads programme hadn't gone ahead, some of this work would never have been found. Ireland had one of the largest archaeological work programmes in Europe in the last decade, with €250m spent.

"A key finding is our understanding of the Iron Age between 700BC and 400AD. We now have a picture of people's lives."

One startling discovery appeared at first glance to be nothing more than a series of holes in a field.

But excavations along the N22 Tralee bypass in Co Kerry yielded what appeared to be a ritual "avenue" 30 metres long, defined by pits that once held wooden posts and which had never been seen here before.

Dating from 2500BC, and possibly used as late as 400AD, the only comparable example was in the UK.

But what was it used for? Experts believe the fact the moon breaks the horizon along the centre of the avenue around November 1 offers a clue.

"This date marked the end of the grazing season when flocks and herds were brought together and animals that could not be maintained were slaughtered and consumed through feasting," Colm Moloney, from Rubicon Heritage Services, says.

In other words, it may have been a ritual site where locals enjoyed a party prior to the onset of a long, cold winter.

But it's not just physical artefacts that have emerged. Insights into how we lived have come to light, including the grooming habits of the nobility, what soldiers took into battle and what our ancestors grew and ate.

Archaeobotanical studies are under way, which reveal that wheat was more commonly grown in Leinster and Connacht than in Munster and Ulster.

A separate study on 5,000-year-old pottery suggests that milk may have been part of the staple diet – up to now, it was assumed cattle were only slaughtered for meat.

Burnt mounds are commonly known to be ancient cooking sites, where meat was boiled in water-filled troughs heated using hot rocks.

But the water could also be used for bathing, and one trough at Glennameade in Limerick is about the same size as a modern bath.

It's also believed that shaving may have had more to do with sacred rites than keeping neat and tidy.

Three double-edged bronze razors have been found on the roads, thought to have been used between 1900 and 1400BC, and experts believed they were a prized item for a small elite.

"If this was the case, it follows that being clean-shaven was quite transformative and would have set an individual apart within their community," NRA archaeologist Michael Stanley says.

"Shaving was not a daily or frequent exercise during prehistory, but was most likely a ritual act reserved for specific ceremonies performed by a barber-surgeon with perceived magical abilities akin to a medicine man or shaman."

Evidence has also been found of the jewellery people wore, with expert Maureen Doyle saying that men and women both wore the same ornaments – brooches, pins, bracelets and rings – but in different ways.

The 7th-century Bretha Etgid notes a man was exempt from liability for injuring another with the pin of his brooch if it was worn properly on his shoulder. A woman was expected to wear her brooch on her breast.

The material used to produce bracelets ranged from silver to glass, gold, antler, boar tusk and stone. The use of particular materials may have been deliberate, Doyle says, to signify rank.

There are also artefacts collected from the Battle of Aughrim in 1691, including a 17th-century shoe buckle, bullets and fragments of a hand grenade.

It's a fascinating treasure trove, and everything found is now the property of the National Museum of Ireland. The museum is also responsible for any remains found on archaeological digs, including those in the cillín.

Many of the infants have since been reinterred, including 94 found at the Ballykilmore site near Tyrrellspass, Co Westmeath. A bog oak sculpture commemorates those buried there.

'Fragments of Lives Past: Archaeological objects from Irish road schemes' takes place next Thursday, August 22, at the City Wall space, Wood Quay, Dublin Civic Offices