The oldest, walled part of Zagreb is definitely setup with a tourist focus. So much so, that it seemed a bit of a ghost town at night. The apartments over the shops were dark and quiet.
We spent our wandering time in the transition area, downhill to the east of the old section, on the way to the more modern downtown. It has the old world flavor, but had more life to it. The first picture below was taken just before we found a stairway down the hill.