This example visualizes global cities with populations above 50,000, using a square-root size scale to encode population magnitude as circle radius on an equirectangular projection. The map renders with a light-styled sphere, graticules, and country boundaries, with semi-transparent teal circles overlaid at city coordinates. Built with React, the visualization uses D3's `geoNaturalEarth1` projection, `geoPath` for map geometries, and `geoGraticule` for the grid. Country shapes come from the World Atlas TopoJSON, while city data is loaded via D3's `csv` parser from Simplemaps' public dataset.