The M3 heritage trail

The M3 motorway continues to reveal new archaeological wonders as its broad corridor progresses relentlessly through Tara's Gabhra Valley. In the townland of Lismullin alone, in an attempt to steer a course to avoid a known barrow, souterrain, monastic site and the strategically-placed fortification of Rathlugh (recently subject to a preservation order), the motorway route has inadvertently impacted on several other previously unrecorded and equally significant archaeological remains. These include a ring-barrow, a complex of souterrains and, of course, an Iron Age temple. The temple was declared a national monument earlier this year, has since been ‘preserved by record' and awaits the bulldozer's bucket.

Attention has now shifted to the nearby souterrains, a subterranean complex of artificial passages and chambers dating to the Early Historic period (2nd half of the 1st millennium AD), which are currently being systematically dismantled. During the course of recent work, a capstone bearing megalithic art has come to light. Megalithic art, like that at Newgrange, dates to the Neolithic Period (the fourth millennium BC) and so this stone is clearly not in its original context. It must therefore have been acquired from a conveniently close-at-hand passage tomb.

Though this example, consisting of concentric circles, nested arcs and zig-zags, bears similarity in style to the decorated stone in the Mound of the Hostages (on the summit of the Hill of Tara), it is unlikely to have come from this particular monument. Perhaps one of the (as yet) unclassified mounds to be found in the Gabhra Valley is the original source of this stone. Sadly, but as forewarned, the course of the M3 motorway though at the heart of Tara's royal demesne has struck an exceptionally rich archaeological seam.