NationNest Thailand Explorer — administrative boundary reference data

Source: Thailand Canonical Administrative Names, William J. Reynolds
https://github.com/DevelopedbyWill/thailand-canonical-admin-names
Inputs: data/v1.0.0/thailand-adm1-polygons-v1.0.0.geojson
        data/v1.0.0/thailand-adm2-polygons-v1.0.0.geojson
        data/v1.0.0/thailand-adm3-polygons-v1.0.0.geojson
Reference validity date in source features: 21 February 2019.
Coverage: 77 provinces, 928 districts, 7,425 subdistrict geometries. This is a historical reference snapshot, not a guarantee of current administrative coverage.
Retrieved: 26 October 2026
Changes: retained geometries; reduced properties to Thai/English names and parent codes; split district and subdistrict features into per-province files; compacted JSON. Display boundaries are simplified references, not cadastral or ownership boundaries.

Data attribution: Copyright (c) 2026 William J. Reynolds
CC BY 4.0: https://creativecommons.org/licenses/by/4.0/

Polygon upstream: piyayut-ch/mapthai
https://github.com/piyayut-ch/mapthai
Copyright (c) 2021 Piyayut Chitchumnong
MIT License:
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Basemap: OpenStreetMap contributors, https://www.openstreetmap.org/copyright

Administrative display names: canonical ADM2 district and ADM3 subdistrict CSV tables in the same repository, joined by TIS-1099 code to repair truncated shapefile names.
Additional upstream name sources acknowledged by the canonical dataset:
https://github.com/thailand-geography-data/thailand-geography-json — Copyright (c) 2023-Present Joe Takara (MIT)
https://github.com/kongvut/thai-province-data — Copyright (c) Kongvut Sangkla (MIT)
https://github.com/GeoThai/data — GeoThai Team (MIT)
The MIT permission and warranty text above also applies to these upstream notices.