Natural=isthmus on way?

When mapping a peninsula as an area, I create a way across the narrowest part of the isthmus as part of the outline. The rest of the outline is naturally all coastline.

According to wiki, an isthmus should be tagged as a node or an area, and that seems perfectly reasonable to me.

However, would it also be appropriate to map an isthmus as simply the coast-to-coast way at the narrowest part? This seems somewhat less arbitrary to me than an area, is easily maintainable, and matches the actual usage of the word (at least in my country).

Since the wiki page and RFC are both very brief, I’m asking if there’s a good reason to not do this, or if this has come up before.


I quite agree with you that, at it’s simplest, an isthmus is a line, at the narrowest part going to the peninsula.

However, in english it is defined as:

A narrow strip of land, bordered on both sides by water, and connecting two larger landmasses.

So it has a length, as well as a width.

For example, here I’ve drawn in red one I know well, and how it’s colloquially perceived in my mind. In blue how it is mapped in OSM (a bit more specific, probably more accurate).

Hope this helps.


Hello sbre,

The reason why these named natural entities are drawn as areas are because then you can know if you are in or out of that area. Also, if you where to draw lines only you would have two lines for each isthmus, making counting them harder.

Natural entities come in points (tree, cave, etc) lines (cliffs, etc) and areas (forest, lake, etc)

In this case an isthmus is best represented as an area, while a node is allowed this must be viewed more as a temporary solution.

The maintainability does not have to be bad. Just follow the coastline and connect the two coastlines on each end. Without gluing it to anything else.