This visualization displays a world map with circles marking cities that have populations exceeding 50,000, sourced from the Simplemaps World Cities Database. The map uses a natural Earth projection via `d3.geoNaturalEarth1` and `d3.geoPath` to render landmasses, graticules, and interiors in SVG. Circle radii are scaled proportionally to population using `d3.scaleSqrt`. The visualization is built with React, D3 v5, and TopoJSON, loading world atlas data from `world-atlas@2.0.2`.