This example renders a world map with city populations using a natural Earth projection. The visualization uses D3’s `geoNaturalEarth1` projection and `geoPath` to draw landmasses, graticules, and country interiors, while scaled circles overlaid onto the map encode each city’s population with a square-root scale. The data comes from the Data Canvas Sense Your City dataset, loaded via `d3.csv`. The React application asynchronously fetches the world atlas and city data, then renders the visualization as an SVG.