|natural = valley|
|Used on these elements|
|Tools for this tag|
A valley is an elongated natural depression flanked by ridges or ranges of mountains or hills, and at least partially formed by fluvial degration.
- Draw a line along the valley bottom and tag it natural=valley. You certainly want to set a name=* too. Note that valleys and waterways are not necessarily congruent. Rivers are often meandering. There may be multiple branches of the river, or no river at all. Therefore, you better ignore waterways in U-shaped valleys, and go for the middle line of the valley bottom instead.
- While linear mapping of valleys is preferred, some valleys are mapped as nodes. Possible reasons include imports and lack of aerial images.
The main purpose of natural=valley features is to tell renderers the name=* of the valley, and where to span that name. Renderers may use hillshading and/or contour lines generated from elevation models to make valleys look more spatial.