Jō-Bō System of Heijō-Kyō – City Planning in Ancient Japan

   

 The plan of Heijō-Kyō

 An aerial photo overlaid by the plan of Heijō-Kyō
In the ancient city planning of Japan, streets formed a grid pattern. This way of planning is called the Jō-Bō system. This system of planning is borrowed from Chang’an, the capital of Tang Dynasty China. Nara (Heijō-Kyō), as the capital of Japan from 710 AD to 784 AD (with a few interruptions), adopted the Chinese grid-pattern system. Suzaku-Ōji Street, the central axis, separated the city into Sakyō, the Left (East) City, and Ukyō, the Right (West) City, each of which was divided into a matrix of nine jō (rows) and four bō (columns). Each city block of 532 meters square bounded by major streets was also called bō. Each bō was again subdivided into 4-by-4 cells called tsubo, the size of which was 133 meters square. Every place in the city was specified by row and column numbers in a way somewhat similar to the Cartesian coordinate system.

The palace site in the center of the north side of the city included the Imperial Palace and government offices. There were two official marketplaces, one each located in the Left and the Right City. Near the palace site, remains of large plots for nobles’ residences have been discovered. These residences sometimes occupied several tsubo. Away from the palace site, each tsubo was divided into smaller plots to provide living quarters for the common people. Nara was abandoned as a capital in 784, and most of its area reverted to rice paddies. The above aerial photo, taken in 1961, is of the central area of Heijō-Kyō, where the ancient plan is well preserved. It shows traces of the old grid pattern in the rectangular reservoirs and the paths between rice fields.

Gekyō, the Outer City, had been added to the northeast side of the city. Major Buddhist monasteries such as Kōfuku-ji and Gangō-ji were situated there, and Tōdai-ji, which is famous for its enormous statue of Buddha, was built adjacent to the area. Due to the influence of these monasteries, this part of the city remained an urban settlement after the capital was moved to Nagaoka-Kyō and later to Heian-Kyō (Kyoto). Gekyō is the core of today’s Nara City. The other ancient capitals of Japan, such as Fujiwara-Kyō (694-710) and Heian-Kyō (794-1868), also adopted grid-pattern planning. This Chinese planning system was widely shared by the East Asian states of the time.


Ancient capitals of Japan in Kansai district.
Digital geographical data are from the Geographical Survey Institute of Japan.

By Kumiko Yamachika, National Defense Academy

Reference

Last Updated: 16/Apr/2001