Everyone has to live and work somewhere.
The street is wide, and smoothly paved, with trees planted along the sides. The houses are mansions and palaces, each surrounded by stone and ironwork walls that are as much decorative as they are protective. These are the summer homes of the Princesses, and ladies of privelage.
You come upon a ruined building in the back section of a city park (or other out of the way area of the city). The ruins are fairly overgrown. All that is really standing is a doorway and its frame. If you pass through the opened door, you travel to a different world. If the door closes, there may not be a doorway back to get you back.