A dry moat, usually with a V-shaped cross-section called *yagenbori 薬研堀. The base of the moat was of earth or stone, so in battle enemy soldiers falling into the moat were often killed or injured, whereas in a water-filled moat *mizubori 水堀 they could swim to safety. Dry moats also gave castles a strategic advantage because the enemy could not use boats to approach the walls. Karabori are associated with medieval fortifications and were large-scale structures. Most mountain castles *yamajiro 山城 had dry moats, but flatland castles *hirajiro 平城 were usually located on low swampy ground so water-filled moats were generally used. An exception is Nagoyajō 名古屋城, a flatland castle built on a plateau: the main ward *honmaru 本丸 is surrounded by a dry moat.
Nagoyajō 名古屋城 (Aichi)