Also termed tamon-zukuri 多聞造, tamon'yagura 多聞櫓 (many listen tower) and tamon nagaya 多聞長屋 (many gate long gallery).
A long, narrow, continuously roofed timber-frame structure *nagaya 長屋 built on a stone faced embankment *ishigaki 石垣, that runs between a castle's corner towers. Classified as a type of castle tower *yagura 櫓. The walls are aligned with the plane of the stone faced embankment and the outer castle walls. The tamon usually has plastered walls and a tiled roof, and was often fitted with loopholes *sama 挾間, and sometimes even a stone-drop *ishi-otoshi 石落し. Sometimes the tamon occupied the majority of the space above the stone faced embankment, protecting the castle wall behind it by stopping rainwater from getting into the earth foundations of the wall, and blocking the narrow path *inubashiri 犬走り on the embankment, thus denying enemies a useful foothold. Between one and three stories in height, the tamon served various functions including a hiding place for troops in wartime, or an armory or storehouse in peacetime.
The name 'tamon' is said to be derived from Matsunaga Hisahide's 松永久秀 (1510- 77) Tamon-jō 多聞城 (1559) in Nara, which had a similar structure. Alternatively, the name tamon may refer to the guardian deity of the north *Bishamonten 毘沙門天, known as *Tamonten 多聞天, whom Kusunoki Masashige 楠木正成 (1294-1336) is thought to have installed as a tutelary deity in one of his castle towers. There are many extant examples, including Hikone-jō 彦根城 Sawaguchi 佐和口 Tamon'yagura where the tamon is used as a connecting tower *watari yagura 渡櫓 flanking the east and west sides of Sawaguchi Gate; Fukuoka-jō 福岡城 South Ward Tamon'yagura, a single-story structure with a double-roofed corner tower; and Kanazawa-jō 金沢城, which has a thirty-bay gallery with two stories that was built as a powder magazine.