README.md

---
license: other
license_name: public-domain-and-cc0-1.0
license_link: https://huggingface.co/datasets/Freonius/jerome-maps/blob/main/README.md#licences
viewer: false
language:
  - en
tags:
  - maps
  - gazetteer
  - natural-earth
  - wikidata
  - jerome
pretty_name: Jerome's world map
---

# Jerome's world map

The world map of the Jerome writing app, which downloads these three files
once and shows the map offline: the countries, regions, rivers, lakes, towns,
major roads and railways of [Natural Earth](https://www.naturalearthdata.com/),
its shaded relief, and a place search over the settlements of
[Wikidata](https://www.wikidata.org/) with an English name. There are no
streets. Jerome pins each file by this repository's commit, its size and its
SHA-256.

| File | What it is |
| --- | --- |
| `world.pmtiles` | Natural Earth 5.1.2 as vector tiles (Mapbox Vector Tile 2, gzipped), zooms 0–7, in a [PMTiles](https://github.com/protomaps/PMTiles) v3 archive; 1:110m at zooms 0–1, 1:50m at 2–3, 1:10m from 4 |
| `relief.pmtiles` | Natural Earth's shaded relief (1:10m, the smaller size) as 256-pixel JPEG tiles, zooms 0–6, Web Mercator, in a PMTiles v3 archive |
| `gazetteer.tsv.gz` | About 1.3 million settlements from Wikidata with an English name and coordinates, each with its country, region and population, as gzipped tab-separated text sorted by a folded key (the format is in Jerome's `crates/maps/README.md`) |

## Layers of `world.pmtiles`

`rank` is a whole number, lower for the more important, from Natural Earth's
scale and label ranks. Names are English (Natural Earth's `NAME_EN`, else its
`NAME`). A feature appears from the zoom Natural Earth gives it; zoom 7 holds
them all.

| Layer | What | Properties | From zoom |
| --- | --- | --- | ---: |
| `water` | Oceans and seas | – | 0 |
| `land` | Land, islands included | – | 0 |
| `lakes` | Lakes and reservoirs | `name` | 0 |
| `urban` | Urban areas | – | 2 |
| `rivers` | Rivers and lake centre lines | `name`, `rank` | 0 |
| `regions` | Boundaries of first-level divisions (states, provinces, regions) | – | 2 |
| `countries` | Boundaries between countries on land: kind country, or disputed for any other line | `kind` | 0 |
| `roads` | Major roads: kind major (highways, beltways, expressways) or secondary; no ferries | `kind` | 3 |
| `railways` | Railways; no train ferries | – | 4 |
| `region_labels` | A point for each first-level division's name | `name`, `rank` | 2 |
| `country_labels` | A point for each country's name | `name`, `rank` | 0 |
| `places` | Cities and towns: capital 2 for a country's capital, 1 for a region's, else 0 | `name`, `rank`, `capital` | 0 |

## How it is made

Jerome's `scripts/build-world-map.ts` builds the three files from inputs
pinned, with their sizes and checksums, in Jerome's `sources.lock.json` and
mirrored in
[Freonius/jerome-sources](https://huggingface.co/datasets/Freonius/jerome-sources):
Natural Earth's GeoJSON from
[nvkelso/natural-earth-vector](https://github.com/nvkelso/natural-earth-vector)
at the release's commit, the shaded relief from naciscdn.org, and the answers
of [QLever](https://qlever.dev/wikidata)'s Wikidata endpoint to the queries in
Jerome's `packages/map-data/queries/`. The tiles are cut with
[geojson-vt](https://github.com/mapbox/geojson-vt) and encoded with
[vt-pbf](https://github.com/mapbox/vt-pbf); the archives and the relief are
written by Jerome's own `map-tool`.

## Licences

- **Natural Earth** vectors and rasters are in the public domain; no
  permission is needed to use them. Made with Natural Earth. Free vector and
  raster map data @ naturalearthdata.com.
- **Wikidata**'s data is available under
  [CC0 1.0](https://creativecommons.org/publicdomain/zero/1.0/). Place names
  from Wikidata.