Ba Da Hutong
Ba Da Hutong was once a red-light district in Old Beijing. The Ba Da Hutong is not a name of a hutong per se but the designation for several hutongs gathered in Dashilar. If you haunt the place long enough, you can find some historic brothels that have been preserved, such as Lin Chun Lou in Zhujia Hutong. The décor of this space is, in particular, stunning.