Laos learning maps — sources and transformations, 19 October 2026

Administrative areas
geoBoundaries gbOpen LAO ADM1, boundaryID LAO-ADM1-31783359.
Source: OpenStreetMap / Wambacher; reference year 2017.
Licence: Open Data Commons Open Database License 1.0 (ODbL).
https://www.openstreetmap.org/copyright
https://opendatacommons.org/licenses/odbl/1-0/
https://www.geoboundaries.org/api/current/gbOpen/LAO/ADM1/
Pinned extract:
https://media.githubusercontent.com/media/wmgeolab/geoBoundaries/9469f09/releaseData/gbOpen/LAO/ADM1/geoBoundaries-LAO-ADM1.geojson

The complete source is scripts/laos-admin-source.geojson. Original metadata is
public/data/laos-admin-source-metadata.json. All eighteen areas are retained:
seventeen provinces, including Xaisomboun (re-established in 2013), and separate
Vientiane Capital prefecture. Vientiane Province is a different answer. Display
spellings are curated; original ISO codes are retained. Shared boundaries are
simplified together at 0.002 degrees with Shapely 2.1.2 coverage_simplify;
coordinates are rounded to six decimals. The derived administrative database is
available as /laos-provinces.geojson under ODbL 1.0. The checked-in source and
builder provide the material needed to reproduce this adaptation. Reference
lines are not navigation, access permissions or a resolution of border claims.

Rivers
Natural Earth vector 5.1.2, 1:10m rivers and lake centerlines, public domain.
https://github.com/nvkelso/natural-earth-vector/blob/v5.1.2/geojson/ne_10m_rivers_lake_centerlines.geojson
https://www.naturalearthdata.com/about/terms-of-use/
scripts/laos-water-source.geojson retains the original selected line geometry
and sourceName. Source names Mekong and Lancang contribute to the Mekong;
Ou is displayed as Nam Ou; Ngun as Nam Ngum; Kong as Sekong. Lines are clipped
to a 0.03-degree buffer of the source-derived land, retaining border reaches;
tiny fragments under 0.025 degrees are omitted. Derived /laos-waters.geojson
uses the ODbL boundary database for clipping and is offered under ODbL 1.0;
the original Natural Earth extract remains public domain. Lines are generalised
river courses, not current shorelines, reservoir outlines or a complete network.

Cities and sights
Twenty curated settlement coordinates are in scripts/laos-map-places.json and
/laos-cities.geojson, in longitude/latitude order, WGS84. Cities are checked
against parent areas with a 0.01-degree allowance for source generalisation.
The curated city inventory is CC0. Savannakhet city is officially Kaysone
Phomvihane; the more familiar name is used in the game and explained in notes.
Sights in src/lib/country-sights/laos.json are representative place pins rather
than entrances. UNESCO property boundaries are not supplied by these maps.

Rebuild at repository root:
  python scripts/build-laos-maps.py
Requires Python 3 and Shapely 2.1.2. No network access is needed to rebuild.
The builder validates source coverage, feature identities and city parents, and
generates all three GeoJSON files, atlas answer pools and place-name lookups.