Map i Gymru: building an OpenStreetMap in Welsh

The draft map

Have a peek at this map of Wales, with place names in Welsh.

https://openstreetmap.cymru

Many people have never seen place names in Welsh such as Aberteifi, Treffynnon or Aberdaugleddau on an online map – or indeed any map.

These names have been used for many generations until the present day, from conversations to road signs to media. The Welsh-language Wikipedia, known to its users as Wicipedia Cymraeg, has articles bearing these names.

Nevertheless they are not usually offered or recognised by the well known proprietary map providers.

In order to build a map in Wales’ own language we at the project have drawn from freely licensed OpenStreetMap data, server software, and documentation. These are all the work of many contributors around the world, and to these people we are very grateful. We are also very thankful to the Welsh Language Unit of the Welsh Government who have funded this early work.

Building on the map

This is a draft map running on a prototype server. It gives you the ability to pan and zoom. As the developer on this project I am very pleased with the results so far.

I will introduce another feature very soon – the ability to embed this map on any website.

Nevertheless you might spot omissions or glitches while it’s being developed, and some big areas for functional improvement.

As I write this we have received a bundle of very useful place name data from the office of the Welsh Language Commissioner, which is itself the fruit of years of dedicated work. This is comprehensive down to the level of villages, and licensed under OGL.

Improving the data

This section contains background if you are interested in improving OpenStreetMap place names and other data.

Imports of the OSM data happen automatically overnight. Some pre-rendering of map tiles is also done, to speed things up.

The ideal OSM data set for place names in Welsh would have a name:cy tag for every single item. We are not there yet.

In the meantime my system uses name:cy tags and some name tags.

name:cy has highest precedence. If you want to add a definitive name in Welsh to anything, edit the map on osm.org and add a name:cy tag. You will need to create a user account if you don’t already have one. Provided your submission is accepted by the community this will guarantee its inclusion on the next nightly update.

Many name:cy tags already exist.


The challenge with the existing data is that some names that we want to use are currently only available from the name tag. That is, many places do not have a name:cy tag.

Understandably OSM contributors haven’t tended to add an identical name:cy tag for Morfa Nefyn, Abersoch, and hundreds of other villages and places.


I’ve tried rendering different versions of the map using different criteria. Enabling all name tags somewhat ruins the ethos and magic of having a map in Welsh. Then huge tracts of Wales vanished when I removed the name tags again!

So I have set the system to use name for these types of places only:

  • ‘village’
  • ‘hamlet’
  • ‘town’
  • ‘island’
  • ‘neighbourhood’
  • ‘square’
  • ‘farm’
  • ‘isolated_dwelling’
  • ‘locality’


For other elements I also have a white list and black list, e.g. ‘Ysgol’, ‘Capel’ and ‘Eglwys’ are on the white list, among others. We will tend to want names containing those words.

name:cy currently overrides all of this however. Do please add name:cy tags via osm.org if you spot errors or gaps, and they will also be available to other projects around the world.

Use and applications in the near future

What you see now is just one possible app that uses the underlying map infrastructure to show a map of Wales.

Having a map like this introduces many exciting possibilities in:

  • learning
  • exploration
  • navigation
  • play
  • research
  • communication.

5 thoughts on “Map i Gymru: building an OpenStreetMap in Welsh”

  1. It’s great to see another choice of map, and interesting to read how you’re processing names to exclude ones that you’re not sure of the language of, but would it be possible to include “obviously Welsh” names such as “Penbanc”? See for example https://www.openstreetmap.org/way/54204031 http://map.atownsend.org.uk/maps/map/map.html#zoom=19&lat=51.99428&lon=-4.980397 . As you’ll know better tham I, Welsh names are often compounds (e.g. with the diminutive “bach”) so I bet you could have a go at whitelisting some names by value.

    PS: Slightly annoying that I have to help improve Google’s maps (via their captcha) to post this!

    1. Andy, thanks for your question.

      I have rendered several draft versions of the map, and had to make judgments on the net benefit of whitelisting a number of different terms.

      For example when whitelisting ‘Canolfan’, ‘Llyfrgell’, ‘Ysgol’ for the name field the results tend to be accurate on the whole with few false positives. But these are blanket whitelists. Other terms have been less beneficial.

      The overall objective has been to produce a map fairly quickly that’s good enough to present to the public. As a project we hope to simultaneously show what’s possible and encourage people to contribute names for streets and buildings in their own milltir sgwâr and/or favourite parts of Wales.

      For anybody reading this who’d like to contribute, by far the best way to ensure that names in Welsh are visible on openstreetmap.cymru AND available to other projects around the world is to update them via osm.org – diolch o galon.

  2. Checkout goo.gl/pVUhf8 for a dataset of place-names and alternatives place-names resulting from the Wales Settlements Project & WikiWales feasibility study.

    This is being merged with the beta dataset at goo.gl/z5DAso provided by the Welsh Language Commissioner for Map i Gymru, and the dataset of settlements in Wales at goo.gl/HLWhdg that have Wikipedia articles.

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