Japan prefecture map

Source: geoBoundaries gbOpen JPN ADM1, boundary ID JPN-ADM1-47310658
Boundary year: 2017. Source providers: OpenStreetMap, Wambacher.
https://www.geoboundaries.org/
https://github.com/wmgeolab/geoBoundaries/tree/9469f09/releaseData/gbOpen/JPN/ADM1

Contains information from OpenStreetMap, which is made available here under
the Open Database License (ODbL) 1.0: https://opendatacommons.org/licenses/odbl/1-0/
Copyright and attribution: https://www.openstreetmap.org/copyright

This derived database is available under the same ODbL 1.0 license at
/map-data/japan.json. Changes: project longitude/latitude into map coordinates,
simplify paths, round coordinates, and add Japanese prefecture names.
Regenerate with: node --experimental-strip-types scripts/generate-japan-map.mjs

The map is a personal travel illustration, not a navigational or legal boundary map.