What are the traditional residential areas in Shanghai?

The most distinctive feature of Shanghai is Shikumen, and the most distinctive feature of Shikumen is the large-scale venue, haha.

However, Shikumen was built by foreign countries before liberation. Many rich people's villas were taken away by the government after liberation and given to ordinary people to live in, so there may be six or seven households in a house number now, but they used to live in one household.