Bhutan learning maps — prepared 18 October 2026

DISTRICTS
geoBoundaries gbOpen BTN ADM1, boundary ID BTN-ADM1-66845921.
Source: geoBoundaries / Wikimedia Commons, author Babbage.
Licence: Creative Commons Attribution 3.0, https://creativecommons.org/licenses/by/3.0/
Year represented: 2010. Twenty dzongkhags, using source ISO 3166-2 codes.
Metadata: https://www.geoboundaries.org/api/current/gbOpen/BTN/ADM1/
Pinned geometry: https://media.githubusercontent.com/media/wmgeolab/geoBoundaries/9469f09/releaseData/gbOpen/BTN/ADM1/geoBoundaries-BTN-ADM1.geojson
Names standardised to Thimphu, Chhukha and Lhuentse. Geometry rounded to
five decimal places. These reference boundaries are not a determination of
international borders and do not resolve Bhutan–China boundary negotiations.

TOWNS
Twenty-two curated town-centre coordinates, in longitude/latitude order.
Includes all twenty district centres plus Phuntsholing and Gelephu.
Every centre is checked against its assigned reference district by the builder.
Names and coordinates can be reviewed in scripts/build-bhutan-maps.mjs.
Town points identify settlements rather than administrative polygons.

RIVERS
© OpenStreetMap contributors, Open Database Licence 1.0 (ODbL).
https://www.openstreetmap.org/copyright
https://opendatacommons.org/licenses/odbl/1-0/
Snapshot: 2026-10-18T23:27:41Z, via the Overpass API.
The published bhutan-waters.geojson is the derived database supplied under ODbL.
Query: [out:json][timeout:60][date:"2026-10-18T23:27:41Z"];way["waterway"="river"](26.7,88.7,28.4,92.2);out tags geom;
Endpoint: https://overpass-api.de/api/interpreter
Named ways are selected using primary and English-name aliases, clipped to
the reference country plus a 300-metre margin, simplified at 0.00008 degrees
and rounded to five decimals. Pieces shorter than 50 metres are omitted.
No straight connectors are invented between source ways. Missing or unnamed
source sections can therefore appear as gaps. Only selected rivers are shown;
this is not a complete network or a navigation map. River names can change
downstream: the Amo Chhu becomes the Torsa, the Puna Tsang Chhu the Sankosh.

REPRODUCTION
Run node scripts/build-bhutan-maps.mjs to download the pinned district source
and query the dated OSM snapshot. For an offline rebuild, supply a directory
containing admin.geojson and osm-rivers.json as the first argument. Generated
files: public/bhutan-{districts,cities,waters}.geojson, src/lib/atlas/bt.ts and
src/lib/atlas/bhutan-places.ts. Previews render from this same geometry.