This is a simple setup of Leaflet (via Mapbox) with d3 to show dots on a map. This can serve as a base for many interesting geographically based visualizations
Nice overview of using d3 + Leaflet. I found this slightly simpler to use than Mike's classic post.
Built with blockbuilder.org
forked from enjalot's block: dots on a map: setup
forked from arimocro's block: Test Velo'v Lyon Markers
Modified http://d3js.org/d3.v3.min.js to a secure url
https://d3js.org/d3.v3.min.js