Wark on Tweed Wark on Tweed Wark on Tweed (usually referred to simply as Wark) is a village in the English county of Northumberland. It lies approximately south west of Berwick-upon-Tweed. It is on the south bank of the River Tweed which marks the border between England and Scotland. The ruins of Wark on Tweed Castle, originally an early 12th century motte-and-bailey, lie at the west end of the village. The border between Scotland and England runs down the middle of the River Tweed, however between the villages of Wark and Cornhill the Scottish border comes south of the river to enclose a
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