麻豆约拍

A look at the River Tweed and its course through the Southern Uplands of Scotland. The Tweed has its source in the Lowther Hills and starts as a tiny stream. As it flows downhill it gets bigger and bigger, with more water entering from other streams and rivers such as the Teviot. These are called tributaries. Finally it reaches Berwick-upon-Tweed, where it enters the North Sea.