Exploring Parisian passages is one of my favorite walking tours. Dating back to the early 19th century these early shopping malls were built to protect pedestrians from mud and horse drawn carriages. Some seem more light and bright, while others are packed with small cafes, antiques, stamp dealers, and even doll house furnishings.
We enjoyed tea and pastries in the bottom left shop while watching shoppers eye the goodies. (For inquiring minds: I had baba au rhum and it was worth every calorie, though I actually lost a little weight on this trip.)