城墙

城墙 refers to a defensive structure built around a city, typically made of stone or brick. It was historically used for protection against invaders and to control access to the city. Unlike modern walls, it often included gates, towers, and other fortifications.

The character 城 (chéng) means 'city,' and 墙 (qiáng) means 'wall.' Together, they literally translate to 'city wall,' emphasizing its role in surrounding and protecting urban areas.

城墙 is commonly seen in historical contexts, especially in ancient Chinese cities like Xi'an, where parts of the original city wall still stand today. It is also used metaphorically to describe barriers or boundaries, such as social or cultural ones.