# External map layer

<figure><img src="https://1672210197-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-LSRNxaH2Ju9Flr7JhJD%2Fuploads%2F9nSDkFYReqshn9TacYDz%2Fimage.png?alt=media&#x26;token=b42c9c23-8453-468d-bc11-3ea230a655db" alt=""><figcaption><p>In Map settings >> External layer</p></figcaption></figure>

{% hint style="success" %}
sample map with swiss topo layer: <https://racemap.com/player/swiss-topo-sample>

URL to call external layer: <https://wms.geo.admin.ch/?SERVICE=WMS&REQUEST=GetMap&VERSION=1.3.0&LAYERS=ch.swisstopo.swissimage&STYLES=default&CRS=EPSG:3857&BBOX={bbox-epsg-3857}&WIDTH=256&HEIGHT=256&FORMAT=image/png>

more about swiss topo. <https://www.geo.admin.ch/en/geo-services/geo-services/portrayal-services-web-mapping/web-map-services-wms.html>&#x20;
{% endhint %}

```
https://wms.geo.admin.ch/
     ?SERVICE=WMS
     &REQUEST=GetMap
     &VERSION=1.3.0
     &LAYERS=ch.swisstopo.swissimage
     &STYLES=default
     &CRS=EPSG:3857
     &BBOX={bbox-epsg-3857}
     &WIDTH=256
     &HEIGHT=256
     &FORMAT=image/png
```

|                            |                                     |
| -------------------------- | ----------------------------------- |
| SERVICE                    | WMS                                 |
| REQUEST                    | GetMap                              |
| VERSION                    | 1.3.0 or 1.1.0                      |
| STYLES                     | empty                               |
| CRS (1.3.0) or SRS (1.1.0) | EPSG:3857                           |
| BBOX                       | {bbox-epsg-3857} a variable         |
| WIDTH                      | 256; same as tile size respectively |
| HEIGHT                     | 256; same as tile size respectively |
| FORMAT                     | image/png or image/jpeg             |
| TRANSPARENT                | true                                |

LAYERS: different, available in GetCapabilities e.g. <https://wxs.ign.fr/`yourkey`/geoportail/r/wms?SERVICE=WMS\\&VERSION=1.3.0\\&REQUEST=GetCapabilities>