This example displays a natural Earth projection world map with country boundaries, graticules, and city markers scaled by population. The visualization uses React to render SVG elements, with d3-geo’s `geoNaturalEarth1` and `geoPath` for the projection and paths, and `geoGraticule` for the grid. City data comes from a CSV of world cities, with population values mapped through d3’s `scaleSqrt`. Land and interior borders are derived from World Atlas TopoJSON via topojson’s `feature` and `mesh` functions.