This example shows a map of New York City ZIP code boundaries, with each postal code drawn as a filled polygon. The map uses d3.geoPath to render the GeoJSON features from a gist, which contains both the polygon geometry and property data such as borough and neighborhood name. The visualization colors each district and includes a longitude/latitude attribute for each ZIP code, enabling geographic context. The GeoJSON file supplies all boundary coordinates and metadata directly, so the rendering relies on d3’s geographic projections to display the polygons in a flat, interactive layout.