城壁

1. Origins, structure, and basic meaning

• Structure: It is read じょうへき. 城 denotes a castle and 壁 a wall, forming a word for a defensive wall surrounding a castle or city.
• Basic usage: It refers to a defensive structure or its surviving remains. In the example, a tourist walks along an old defensive wall.
  • 観光客は古い城壁の上を歩いた。

2. Common pitfalls and similar expressions

• Defensive walls versus stone structures
  • 城壁 emphasizes a wall's defensive role, while 石垣 emphasizes its construction from stacked stone. The terms can overlap for a stone defensive wall, but a stone retaining wall is not necessarily a castle or city wall.