The River Tweed is a river of northern Britain, which forms the border of England and Scotland for part of its length. It is 156 kilometres (97 miles) long and rises on Tweedsmuir in south-western Scotland, the moor being the watershed of the Tweed, Annan and Clyde river systems. Flowing northwards and then eastwards it passes through Peebles, Melrose and Kelso. Shortly before Coldstream, which lies on the north bank, the river becomes the Anglo-Scottish border for some 27 km. A little way west of Berwick upon Tweed, the river enters England for a few short miles; it flows into the North Sea at Berwick. It is a noted sporting river, particularly for its salmon fisheries. At Paxton, west of Berwick, it is crossed by the Union Bridge, the oldest suspension bridge in Europe, and at Berwick by the Royal Border Bridge, a magnificent railway viaduct designed by Robert Stephenson (the name is misleading as the river does not form the border at this point). Several other handsome bridges span the river.
The woven woolen cloth known as 'tweed' has no connection with the river name, but is a corruption of 'tweel' ('twill').