This visualization layers city population data onto a world map using a natural Earth projection. Semi-transparent green circles, sized with a square-root scale, represent each city’s population, with larger circles indicating more populous urban centers. The map includes geographic graticules, land masses, and country interiors rendered via `d3.geoNaturalEarth1` and `d3.geoPath`. The React app loads TopoJSON world-atlas data and CSV city coordinates through custom hooks, with map features styled distinctly in light grays.