Points on a Map
A world map displays cities with population over 50,000 as semi-transparent teal dots, projected using the Natural Earth projection. The visualization layers graticules, land masses, and country borders from World Atlas TopoJSON, with city coordinates from a Simplemaps CSV. React manages the component state while D3’s `geoNaturalEarth1`, `geoPath`, and `geoGraticule` handle the geographic rendering, and `csv` and `json` load the external datasets.