Crime Vis UK is an interactive map of the United Kingdom that visualizes crime data at the county level. It shows a geographic overview with countries and county boundaries, where users can click on a region to select it and view detailed information. Built with D3 v4, the visualization uses `d3.geoMercator` and `d3.geoPath` to render the map from TopoJSON data, while `d3.zoom` supports pan and zoom interactions. Styled with CSS for hover and active states, the map renders as SVG with animated transitions, drawing from local JSON files for UK topology and boundaries.