inner moat; moat within the castle walls
Refers to the inner moat of a Japanese castle, typically the one directly surrounding the main enclosure (honmaru). Used in historical and architectural contexts.
The inner moat of Edo Castle still remains around the Imperial Palace today.
内堀と外堀では、内堀の方が防御上重要だった。
Between the inner and outer moats, the inner moat was more important for defense.
Tourists walked around the castle's inner moat taking photos.