There are apparently 9,866,539 buildings in all of the Netherlands. And Waag.org has just plotted them all on a map and colour coded them based on the year of their construction (via Information Aesthetics).

Here’s what Amsterdam looks like:

As to be expected, you can see how the city grew out from its historic core. What would it make the map even better though, is if you could turn off “layers” and see each time period in isolation.

If you’re interested in this sort of thing, here’s a similar map of Portland.