1. READ/play the text
2. CLICK the picture (and video)
3. TRY this: These are two lakes in the Lake District. They are Buttermere (front) and Crummock Water. Find them on a map, then count how many other lakes you can see on your Lake District map.

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Lakes and deltas

Lakes are some of the most striking features of valleys - but they were not formed by rivers.

In fact, in time, rivers will destroy all lakes in their paths.

You can see this happening where sand, silt and mud carried by rivers is dropped in the still waters of the lake in the shape of a wedge of new land called a delta.