This visualization shows the relationship between eruption time and waiting time for the Old Faithful geyser dataset, using density contours to highlight areas of high data concentration. The contours are computed with `d3.contourDensity` and rendered as SVG paths via `d3.geoPath`, with colors mapped through `d3.scaleSequential` and `d3.interpolateGreens`. The axes are drawn with `d3.axisBottom` and `d3.axisLeft`, and the contour bandwidth updates interactively based on mouse movement across the page, demonstrating dynamic resmoothing of the density estimate.