Outstanding work, purblind_horus.

If there's ever going to be another version, here's a couple of ideas for you to consider:

- Instead of stacking placemarks on top of one another, draw a single extruded polygon at the height of the highest placemark. This would provide much better visual clarity, and also solve some of your performance problems.

- There's a lot of temporal information in your post, but no way to see it (beyond reading the descriptions). An idea would be to take the center of the city (Baghdad, for example) as being the most recent data point and then draw a single spiral out from the center (perhaps making several full revolutions), drawing polygons at regular intervals to indicate both the were and when.