Map drawn by Stephen Hannon.
Courtesy of Brian Shaw
The Barrow gorge extends from near Graiguenamanagh for ten kilometers south toward New Ross. The gorge is wedged between the Blackstairs mountains to the east and Brandon Hill to the west. Here the river is up to 75 metres below the flanking country as it forces a route from the midlands south to the sea at Waterford Harbour .
Mid-way along the gorge where a small tributary breaks the slope, the early Christian and medieval monastic site of St. Mullin’s is located. This serene spot was the burial place of the kings of south Leinster , many of whom belonged to the McMurrough Kavanaghs.
The Barrow gorge marks a dramatic change in the regime of the river. Upstream the river is sinuous and sluggish, whereas its course is more direct and its flow faster through the gorge.
Other south-flowing rivers also change regime and force their way southwards out of the midlands through similar gorges or gaps, for example the Slaney near Bunclody, the Nore at Inistioge, the Shannon at Killaloe.
There has been much speculation about why these rivers follow such distinctive routes. Nearly 150 years ago J.B. Jukes claimed the rivers developed on a rock surface that has now been worn away, with the result that their courses are superimposed on the present landscape.
More recent interpretations include visualizations of parts of southern Ireland being subject to uplift (sometime in the last thirty million years), with the rivers somehow managing to maintain their routes during the slow uplift. Another possibility is that the gorges acted as outlet channels for large volumes of fast-flowing glacial meltwater during the Ice Age. These powerful flows may have contributed to the depth and shape of the gorges.