1 Middle gate. The second or inner gate on the north-south axis of a temple compound in the ancient period. It was erected some distance behind the main gate *nandaimon 南大門, on the same axis, and was the principal entrance to the sacred precinct. A roofed, semi-enclosed corridor *kairō 回廊 was attached to each side. Although no chūmon remain from the Asuka period, such gates were believed to be two-storied from the early 7th century through the Nara period. The Chūmon at Hōryūji 法隆寺 (founded 607) has Guardian figures, Niōzō 仁王像, that are placed in bays on either side of the entrance bays. However, with the arrival of new Buddhist sects such as Shingon 真言 and Tendai 天台 in the 9th century, the middle gate was either greatly reduced in size and importance or eliminated altogether. In the Zen sect, tradition has it that the gates known as *sanmon 三門 and *mon 門 of the Zen temple are descendant of the chūmon.
2 In an aristocratic dwelling shinden 寝殿 of the Heian period, the gates partway along the corridors *chūmonrō 中門廊, connecting the residential quarters tai-no-ya 対の屋, and the fishing or fountain pavilions tsuridono 釣殿 or izumidono 泉殿. See *shinden-zukuri 寝殿造.
3 The gate dividing the outer tea garden *sotoroji 外露地, and the inner tea garden *uchiroji 内露地, of a teahouse. The chūmon serves as a symbol to mark the boundary between the relatively profane world of the outer garden and the pure "wilderness" of the inner garden. It is also the spot where the host of the tea gathering usually meets his guests. Compared to the outer gate at the entrance to the *roji 露地, the chūmon is light in construction, usually with a roof made of cogongrass, cypress bark, bamboo, or *yamatobuki 大和葺 (the technique in which boards are placed in two rows vertical to the ridge of the roof). In addition to wood and splint doors, there are bamboo lattice doors takekōshido 竹格子戸, and wicker doors ajirido 網代戸. The gate posts are typically logs and the entire structure is of the *udegimon 腕木門 (roof and bracket gate) type. Several of the trump stones *yaku-ishi 役石, such as the guest's stone *kyaku-ishi 客石, host's stone teishu-ishi 亭主石, and the step-over stone *norigoe-ishi 乗越石, are placed on either side of the chūmon. In some cases, the under-the-door stone tozuri-ishi 戸摺石, is placed beneath the gate door. Sometimes the straddling gate or *nakakuguri 中潜 replaces the chūmon. The use of chūmon in roji is associated with the design of Kobori Enshū 小堀遠州 (1579-1647).