You start with promising looking doors:
Dr. Frankenstein: "What knockers!"
Inga: "Oh, thank you doctor."
The time to visit is morning. The understanding between the city and the property owners encourages access, but you will have less luck in the afternoon and almost none in the evening.
Some doors will be wide open, just stroll on it.
|A sealed over well in a secret courtyard|
The appeal of traboules is a little difficult to explain. I think a person from a big city might look at them and just see dimly lit passages and hallways, only noting that in a lot of places they have remained undeveloped, with peeling paint and dingy colors.
Then you might as well stay home and watch the antics of the Kardashian sisters.