Tiles: Mapbox.com Aerial
Example #5d - Clickable Clustered Marker Example using Icons (Technique 4)
This demonstrates how to add clickable clustered markers to the BA3 Altus Mapping Engine. Eight markers are added in the Washington DC area. The tile set here is the aerial tiles from Mapbox.com. Jsfiddle forces the use of https servers for tiles, but almost any tile server is possible in your own apps. See http://tinyurl.com/h8wahej for details.
Maps: © Mapbox © OpenStreetMap