Vienna's was my first. I noticed from a distance that its City Hall (Rathaus) was literally a giant Advent calendar, with corresponding numbered windows -- curtained. Beginning on the the 1st of December, the appropriate covering is removed, revealing a Christmas scene. This obviously continues until the 24th -- I could see the centrally located "24". I had to move in for a closer look. I discovered that this Christkindlmarkt is the larger, more commercial of Vienna's numerous Christmas markets.
Yes, there are more -- many more.
Yes, there are more -- many more.