River Lugg River Lugg The River Lugg () rises near Llangynllo, Powys. It flows through the border town of Presteigne, Wales then through Herefordshire, England, to the south of Leominster where it meets a tributary, the River Arrow. Its confluence with the River Wye is at Mordiford, downstream of Hereford and from its source. Below Leominster the river was made navigable under the "River Wye & Lugg Navigation Act 1696" for improving the River Wye, and had pound locks. Despite several attempts to improve it, including making flash locks against bridges, the river was probably never a satisfactory navigation. Commercial navigation probably
England–Wales border then runs westwards to the River Teme, and follows the river southeastwards through Knighton before turning south towards the River Lugg at Presteigne, which is within Wales. The boundary continues southwards across hills to the River Wye, and follows the river upstream for a short distance to Hay-on-Wye, on the Welsh side of the border. It continues southwards and rises through and across the Black Mountains, following the Hatterall Ridge past Llanthony on the Welsh side and Longtown on the English side, to reach the River Monnow near Pandy. It then generally follows the river, past Pontrilas (in England) and