In ancient Japan, a complex of buildings within the Imperial Palace used for affairs of State, enthronement ceremonies, and audience with foreign envoys. As a rule the chōdōin was located in the center of the Imperial Palace facing *suzakumon 朱雀門 (red bird gate). It included three parts: the daigokuden 大極殿, the chōdōin and the chōshūden 朝集殿. It was first used in Nagaokakyū 長岡宮 (784). The term, chōshūden was already in use before the construction of Heijōkyū 平城宮. Chōdōin remains were at Naniwa no miya 難波宮 during the Emperor Shōmu 聖武 Reign (724-49); at Shigaraki no miya 紫香楽宮 (a detached palace); Fujiwarakyū 藤原宮 (694-710), Heijōkyū 平城宮 (710-80); Kunikyū 恭仁宮 (740-44); Nagaokakyū; and *Heiankyū 平安宮.
At the original Heijōkyū, the first chōdōin was built in the center, while the second chōdōin was built on the east side of the palace facing mibumon 壬生門. The chōdōin often burned down at the Heiankyū, but the complex of buildings were rebuilt each time, until it was burned down in 1177.
The chōdōin at Fujiwarakyū, at the second Heijōkyū, at Naniwa no miya, at the Nagaokakyū, and at the Heiankyū were approximately the same construction. The chōdōin at Fujiwarakyū differed by having the daigokuden, chōdōin, and chōshūden in line from north. The daigokuden was a building which the Emperor visited and therefore it contained an imperial throne. The perimeter of the chōdōin was surrounded by a corridor, and had a gate that opened to the south. The chōdōin was where subjects were seated when discussing administrative business or ceremonies.
Later there were eight buildings at Nagaoka no miya and twelve buildings at other palaces. They were surrounded by corridors or packed mud fences *tsuiji 築地. The garden which surrounded the chōdōin is called chōtei 朝庭, and subjects stood a line during a ceremony. The gate is opened on the south side. Chōshūden is where the assembled subjects waited until the time for a ceremony, and two buildings are arranged on left and right of south gate of the chōdōin.
A late example of the chōdōin had a podium and base stone, a tiled roof, and was painted red. We can see a part of it on the worshipping hall of Heian Jingū 平安神宮 which was built in 1895 from a copy of the daigokuden at the Heiankyū. Over time, the chōdōin became smaller.