Cambodia learning maps — sources and transformations, 22 October 2026

Administrative areas
geoBoundaries gbOpen KHM ADM1, reference year 2017.
Original sources: OpenStreetMap / Wambacher.
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/KHM/ADM1/
Pinned complete source:
https://media.githubusercontent.com/media/wmgeolab/geoBoundaries/9469f09/releaseData/gbOpen/KHM/ADM1/geoBoundaries-KHM-ADM1.geojson

scripts/cambodia-admin-source.geojson contains the complete original geometry;
public/data/cambodia-admin-source-metadata.json retains source metadata. All
twenty-four provinces and the separate Phnom Penh municipality are included,
including Tbong Khmum, created from Kampong Cham in 2013. ISO codes are retained;
English display spellings are curated. Shapely 2.1.2 coverage_simplify simplifies
shared boundaries together at 0.001 degrees. Coordinates use six decimals.
The adapted database is downloadable at /cambodia-provinces.geojson under ODbL
1.0. These reference boundaries do not resolve border claims or indicate access.

Waters
Natural Earth vector 5.1.2, 1:10m rivers/lake centerlines and lakes, public domain.
https://github.com/nvkelso/natural-earth-vector/blob/v5.1.2/geojson/ne_10m_rivers_lake_centerlines.geojson
https://github.com/nvkelso/natural-earth-vector/blob/v5.1.2/geojson/ne_10m_lakes.geojson
https://www.naturalearthdata.com/about/terms-of-use/
scripts/cambodia-water-source.geojson retains the selected original geometry
and source names. Mekong, Tonle Sap and Srepok retain their names; Kong is
displayed as Sekong. Both source Tonle Sap line features contribute to the
river. Tonlé Sap from the lakes dataset supplies the separate lake polygon.
Rivers are clipped to a 0.03-degree buffer of the source-derived country land;
line fragments shorter than 0.025 degrees are omitted. The adapted water
database, /cambodia-waters.geojson, is offered under ODbL 1.0 because it uses
the administrative database for clipping; the original Natural Earth extracts
remain public domain. The lake polygon is a generalised reference outline,
not a seasonal maximum, flooded-forest extent or present-day shoreline.

Cities and sights
Twenty curated settlement coordinates, in WGS84 longitude/latitude order, are
in scripts/cambodia-map-places.json and /cambodia-cities.geojson, dedicated to
the public domain under CC0. The builder checks each city against its parent
province or municipality, allowing 0.01 degrees for generalised boundaries.
Sixteen sights in src/lib/country-sights/cambodia.json are reference pins rather
than confirmed entrances. M-13, Tuol Sleng and Choeung Ek use UNESCO's component
coordinates: https://whc.unesco.org/en/list/1748/maps/
Other archaeological sites use curated monument or landscape reference points.
The learning map does not supply UNESCO property or buffer-zone boundaries.

Rebuild at the repository root:
  python3 scripts/build-cambodia-maps.py
Requires Python 3 and Shapely 2.1.2. No network is needed. The builder regenerates
the three GeoJSON layers, atlas answer pools and place-name lookups, validating
coverage, unique area codes, valid geometry and settlement parents.