This example maps the locations of Brooklyn Public Library branches as orange points over a green choropleth of Brooklyn neighborhoods. The map uses a D3 geoMercator projection and d3.geoPath to render GeoJSON boundaries, while library coordinates are loaded from a CSV and drawn as SVG circles. Hovering over a point enlarges it and displays a tooltip with the branch name, phone number, and accessibility status. The visualization is built with D3 v7 and renders entirely as SVG.