This example displays a natural Earth projection world map with semi-transparent teal circles sized by each country’s 2018 population estimate, using d3.geoNaturalEarth1, d3.geoPath, and d3.geoCentroid to position circles at country centers. A d3.scaleSqrt maps population values to circle radii, and a custom size legend shows graduated tick marks. Countries missing data appear pink, and hovering highlights them turquoise. The visualization loads UN population CSV data and TopoJSON world geometry via d3.csv and d3.json, renders SVG paths and circles, and supports zooming through d3.zoom.