This property is used on place=city/town (and other place=* of type settlement) to tag the capital of a country or administrative divisions within countries.

How to map

Capitals not tagged as city or town

Not all country capitals fit into the definition of place=city/town because of size or of definition. Please join discussion on Talk page about tagging.

[W] Ngerulmud - place=village 4244310289node 4244310289
This government complex is located 2 km from the center of the town of Melekeok, population 271. The largest town and former capital of Palau is 20 km away in Koror City, population ~11,200.
[W] Funafuti - place=municipality 3376265049node 3376265049 and also place=atoll on 447736425way 447736425
The whole atoll is designated the capital, and currently this is mapped as a municipality rather than a specific settlement
[W] Vatican City - place=suburb 424311883node 424311883
Since it it's a part of Rome and depending on it.

Retrieving capitals from boundary relations

relation Relations of type=boundary+boundary=administrative include the role role admin_centre. The role members can used to get the capitals of countries (admin_level=2 on relation) and other capitals depending admin_level=* on relation.

The following Overpass API query (link) gets all national admin_centres of the world: 

relation["admin_level"="2"]["type"="boundary"]["boundary"="administrative"];
node(r:"admin_centre");
out meta;

The following Overpass API query (link) gets all admin_level=4 admin_centres of Germany. The country and admin_level can be adjusted. 

{{geocodeArea:Germany}}->.searchArea;
relation["admin_level"="4"]["type"="boundary"]["boundary"="administrative"];
node(r:"admin_centre");
node._(area.searchArea);
out meta;

As of 2016 the admin_centre role can't be used in databases created by osm2pgsql: We do not have this information in the database. osm2pgsql does not have membership information and nodes as relation members do not make it into geometries.

See also

External links

Maps where capitals are clearly visible: