>>55367
>I figured the blueish patch in the south isn't water, but what is it?
Empty farmland. You can see it in use in earlier dates.

>How does it help with erosion?
Every row of shrubs along the countour lines is perpendicular to the direction of surface runoff.

>>55376
Nördlingen is what every crater city wishes it could be.

>Always thought pivot irrigation farms looked cool.
They're a good contrast to all the right angles in cropland. Or the desert.

>And while we're on the subject of curious mediaeval cities, supposedly Bologna Italy had skyscrapers during the Renaissance.
Cramped and ominous. I love it.