What idiom is used to describe a place with many bad people?

Cang Gui Na Su (also known as: Dirty people)

Pronunciation cáng gòu nà wū

Explanation: Dirty, dirty: dirty things. Contains and contains dirty things. It is a metaphor for hiding or accommodating bad people and bad things.

Source "Zuo Zhuan·Xuan Gong Fifteenth Year": "The proverb goes: 'The superior and inferior are in the heart, the rivers and lakes accept dirt, the mountains and rivers hide diseases, and the jade and jade hide the flaws.' The Tao."

An example is probably what Wang Siren said in the late Ming Dynasty: "Kuiji is a place for revenge and avenging shame, not a place for ~" (Lu Xun's "Collection of Qie Jie Ting's Essays·Nü Dia").

Abalone House

Pronunciation: bào yú zhī sì

Definition: A shop selling salted fish. It is a metaphor for a place where bad people gather. Abalone: ??A pickled fish with a fishy smell. The shop selling pickled fish is called Abalone House, which is a metaphor for a place where villains gather.

Example: A wise man sees wisdom, a benevolent man sees benevolence, and he enters without knowing the smell. What is this? ★"Preface to "Record of the Appearance of Officialdom"" by "The Appearance of Officialdom" in the Qing Dynasty by Liu Xiang of the Han Dynasty: "Living with good people is like entering the room of Lan Zhi and not hearing about it for a long time." Living with evil people is like entering a house full of abalone. If you don’t smell the smell for a long time, you will be transformed by it.” (Explanation: Living with noble people is like entering a house filled with the fragrance of orchids. As time goes by, the house itself will be filled with fragrance due to the edification, so you can no longer smell the fragrance of orchids; living with people of low quality is like entering a market selling abalone. It has become smelly, so abalone no longer smells bad. This shows that the environment can change a person.

The meaning is a metaphor for bad people going deep into society and spreading everywhere.

Source: "Chaozhou Governor Xie Shangbiao" by Han Yu of the Tang Dynasty: "An evil minister and a traitor live in the chess place."