Berthin Brook
The Berthin Brook is a minor right bank tributary of the River Usk in Monmouthshire, in south Wales. Flowing north from New Inn initially, it turns east at Little Mill to flow along a former glacial meltwater channel past the former Royal Ordnance Factory site at Glascoed and by Rhadyr to join the major river 1 km north of the town of Usk. At the height of the last ice age, the Usk valley glacier reached as far down the Usk valley as Little Mill and sediment-laden meltwater created a valley sandur over which the post-glacial Berthin Brook now flows.
