“People mountain people sea"
Used to refer to a heavily crowded place
Neutral
Sea of people
None
None
《水浒全传》(Shuǐ Hǔ Quán Zhuàn) by 施耐庵 (Shī Nài Ān). The novel has many different English names, including "Water Margin" and "Outlaws of the Marsh."
This chengyu is from a line in the work listed in the "Origin" section above