Sonnenburgstraße or Suncastle street is a small quiet street divided by a fountain near Westbahnhof. It is located in Wilten , the oldest part of Innsbruck.
On the street shield you can read about the history and the name of the street.
When in Budapest, I remember the guide made us pay attention that the window ornaments were different for every floor. Same for those facades.
I bet these are really nice flats to live, with ceillings over 3m and beautiful old stairways.