This example displays a world map with dots marking cities, sized proportionally to population via a square-root scale. The map uses a Natural Earth projection and includes graticules and country borders. The visualization is built with React and D3 v5, leveraging `geoNaturalEarth1`, `geoPath`, and `geoGraticule` for geographic rendering, while city data comes from the Data Canvas Sense Your City dataset. Circles are positioned using the projection and styled with opacity.