You're looking at the the star fort of Bourtange in the Netherlands. It sure looks fantastic, but there's a wily logic behind building a fort in such a shape. Turns out, a circular fortification of the medieval era was vulnerable to cannon fire. All the crazy angles and moats surrounding the star-shaped fort was made it easier to defend.
There's no danger of an invading horde today, but these star-shaped formations are so darned picturesque that I wish they'd build more of these instead of ho-hum suburbs and strip malls.
If you like the Bourtange fort above, check out this article written by one of our favorite bloggers, Shaun Usher (better known as deputy dog). He has compiled 6 communities with intriguing bird's eye shapes as can be seen on Google Maps. He even turned the caps on for us: Link - Thanks Dave!
There's a really nice one in Lille, France - you have to pass through an outer ring of stellated defences (not knowing where you need to go, and probably with defenders dropping things on you from above) and then you're faced with another inner set of stellated defences.
This is why spies drawing maps of defences were so important in those days.