tcc-topojson

TopoJSON world map with 330 polygons matching the Travelers' Century Club destination list. No existing open-source project provides this — NomadMania's regions are proprietary, TCC publishes no polygon data, and topojson/world-atlas is countries-only.

Files

Two files are published, both covering all 330 TCC destinations:

| File | Size | Description | |------|-----:|-------------| | tcc-330.json | ~248 KB | Full polygons for every destination | | tcc-330-markers.json | ~296 KB | Tiny territories (< 1 000 km²) replaced with centroid point markers; better for world-scale rendering |

In tcc-330-markers.json the 83 smallest destinations (Nauru, Liechtenstein, Grenada, most Caribbean islands, etc.) appear as Point geometries with "marker": true in their properties, while the remaining 247 larger territories keep their polygon shapes. Both geometry types share the same properties schema and tooltip behaviour.

Usage

CDN (jsDelivr)

https://cdn.jsdelivr.net/npm/@rembish/[email protected]/tcc-330.json
https://cdn.jsdelivr.net/npm/@rembish/[email protected]/tcc-330-markers.json

npm

npm install @rembish/tcc-topojson

Package page: npmjs.com/package/@rembish/tcc-topojson

JavaScript

const resp = await fetch(
  "https://cdn.jsdelivr.net/npm/@rembish/[email protected]/tcc-330.json"
);
const topology = await resp.json();

D3.js — polygons only

import { feature } from "topojson-client";

// All objects are merged (handles both single- and multi-object topologies)
const allFeatures = Object.values(topology.objects)
  .flatMap(obj => feature(topology, obj).features);

const projection = d3.geoNaturalEarth1();
const path = d3.geoPath(projection);

svg.selectAll("path")
  .data(allFeatures.filter(f => f.geometry.type !== "Point"))
  .join("path")
  .attr("d", path)
  .attr("fill", d => visited.has(d.properties.tcc_index) ? "#4a9" : "#ccc");

D3.js — markers file (polygons + point circles)

import { feature } from "topojson-client";

const resp = await fetch(
  "https://cdn.jsdelivr.net/npm/@rembish/[email protected]/tcc-330-markers.json"
);
const topology = await resp.json();

const allFeatures = Object.values(topology.objects)
  .flatMap(obj => feature(topology, obj).features);

const polygons = allFeatures.filter(
  f => f.geometry.type === "Polygon" || f.geometry.type === "MultiPolygon"
);
const markers = allFeatures.filter(f => f.geometry.type === "Point");

// Draw polygon features
svg.selectAll("path")
  .data(polygons)
  .join("path")
  .attr("d", path)
  .attr("fill", d => colorByRegion(d.properties.region));

// Draw point markers
svg.selectAll("circle")
  .data(markers)
  .join("circle")
  .attr("r", 3)
  .attr("cx", d => projection(d.geometry.coordinates)[0])
  .attr("cy", d => projection(d.geometry.coordinates)[1])
  .attr("fill", d => colorByRegion(d.properties.region));

Feature properties

All 330 features in both files share this schema:

| Property | Type | Description | |----------|------|-------------| | tcc_index | number | TCC destination number (1–330) | | name | string | Destination name | | region | string | TCC region | | iso_a2 | string \| null | ISO 3166-1 alpha-2 code | | iso_a3 | string \| null | ISO 3166-1 alpha-3 code | | iso_n3 | number \| null | ISO 3166-1 numeric code | | sovereign | string | Sovereign state name | | type | string | "country", "territory", "disputed", "subnational", or "antarctic" | | marker | boolean | true if this feature is a Point marker (markers file only) | | area_km2 | number \| null | Area in km² (markers file only, for classified features) |

Coverage

| Region | Count | Indices | |--------|------:|---------| | Pacific Ocean | 40 | 1–40 | | North America | 6 | 41–46 | | Central America | 7 | 47–53 | | South America | 14 | 54–67 | | Caribbean | 31 | 68–98 | | Atlantic Ocean | 14 | 99–112 | | Europe & Mediterranean | 68 | 113–180 | | Antarctica | 7 | 181–187 | | Africa | 55 | 188–242 | | Middle East | 21 | 243–263 | | Indian Ocean | 15 | 264–278 | | Asia | 52 | 279–330 |

Building from source

Prerequisites: Python 3.12+, Node.js (for npx mapshaper).

make all

Full pipeline:

1. venv — creates .venv and installs Python dependencies
2. check — lint (ruff, black), type-check (mypy), tests (pytest, ≥ 80% coverage)
3. download — fetches Natural Earth 10m shapefiles and the Trubetskoy Europe–Asia boundary
4. build — assembles 330 GeoJSON features via direct matches, admin-1 merges, transcontinental clips, island extractions, and Antarctic wedges → output/merged.geojson
5. simplify — runs mapshaper at 3% vertex retention → output/tcc-330.json (~248 KB)
6. markers — replaces polygons < 1 000 km² with centroid point markers → output/tcc-330-markers.json (~296 KB)
7. validate — checks all 330 indices are present and valid
8. dist — copies both files to the repo root

Tuning simplification

The simplification level defaults to 3% (vertex retention) and is controlled by the SIMPLIFY environment variable:

# More detail, larger file (~340 KB)
SIMPLIFY=5% make simplify markers

# More aggressive, smaller file (~204 KB)
SIMPLIFY=2% make simplify markers

Tip: 3% was chosen after visual comparison — it matches world-110m.json quality at world scale while cutting the original 9% output by more than half.

Visual testing

A browser-based viewer is included:

make serve
# → http://localhost:8000/viewer.html

The viewer renders all 330 features coloured by TCC region. A Full / Markers toggle lets you switch between the two files. Hover any feature for a tooltip with name, region, sovereign state, TCC index, ISO code, and area.

Data sources & attribution

• Natural Earth 10m — public domain
• Trubetskoy Europe–Asia boundary — Sasha Trubetskoy, free with attribution

Changelog

1.2.0

• Publish under @rembish/tcc-topojson scoped npm package

1.1.0

• Add tcc-330-markers.json: 83 tiny territories (< 1 000 km²) replaced with centroid point markers for cleaner world-scale rendering
• Reduce default simplification from 9% → 3%, cutting file size by ~52% (524 KB → 248 KB) with no visible quality loss at world scale
• SIMPLIFY env var for tunable simplification level (SIMPLIFY=5% make simplify markers)
• make serve for one-command local preview
• Interactive viewer with Full / Markers toggle, per-region colour legend, and file-size display

1.0.0

• Initial release: 330 TCC destinations as TopoJSON polygons

License

CC-BY-4.0 — see LICENSE for details.