Lord Maximus at Dungeons N Dragons posted A Fantastic Collection of Maps for RPGs.
From the post,
This great collection of Dutch city maps created by Joan Bleau in 1649 entitled Tooneel der Steeden (Views of Cities) is just such a resource. They seem so strange, so unique, and yet so natural at the same time. I honestly believe a quick glance at these will get any GMs mind overflowing with ideas for their next session. Maybe it’s the painstaking attention to detail, or perhaps the fact that these are real maps of real cities, either way these are perfect for role playing games.
I really like how they look, and it’s interesting what the layout of the cities says about their purpose — defense was a significant element of their construction.