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
Guaporé River Guaporé River Guaporé River () is a river in western Brazil and northeastern Bolivia. Its Bolivian name is Río Iténez. It is long; of the river forms the border between Brazil and Bolivia. The Guaporé River is part of the Madeira River basin, which eventually empties into the Amazon River. The Guaporé River crosses the eastern part of the Beni savanna region. It forms the border of the Guaporé Biological Reserve, and is fed by rivers originating in the reserve, the São Miguel, Branco, São Simão, Massaco and Colorado. About 260 fish species are known from the Guaporé River basin,