In a significant archaeological discovery, postholes and other remnants of what is believed to be a dwelling for the empress at the Japanese imperial family’s official residence have been unearthed in Kyoto, the ancient capital.
These findings offer a fascinating glimpse into the history of the Japanese imperial family, Heian-kyo (the administrative center of the Heian period), and the cultural exchanges between Japan and China during this era.
The archaeological remains are believed to belong to the Tokaden pavilion, a structure used as a residence for the empress and female palace attendants. References to the Tokaden pavilion can be found in Heian literature, including renowned works like “The Tale of Genji” and “The Pillow Book.” During the Heian period, which spanned from 794 to 1185, Heian-kyo (known today as Kyoto) served as the emperor’s official residence.
These remains are the first to be definitively linked to a building within this historical complex. The excavation took place in the northwest part of the residence, where the Tokaden pavilion and the Kokiden pavilion were believed to be situated.
During the excavation work carried out by the Kyoto City Archaeological Research Institute in 2015, five postholes were identified, each with diameters ranging from 1.2 to 1.5 meters, arranged from north to south with distances of approximately 3 to 2.1 meters between them. This evidence suggests that these holes were used for burying pillars directly into the ground, without the use of foundation stones.
To confirm the precise positioning of these holes, researchers consulted a document dating back to the Edo period (1603-1867), which detailed the layout of the palace buildings. Their findings aligned with the positions of the holes, indicating that they were part of the southwest section of the Tokaden pavilion. This section extended about 12 meters from west to east and about 27 meters from north to south.
In addition to the postholes, an arrangement of stones forming an L-shaped ditch was discovered in the southwest corner of the Tokaden. This ditch, designed to channel rainwater from the roof, was similar to another found in the northern part of the Kokiden pavilion. A foundation stone was identified between these stone ditches, which researchers believe could be remnants of a corridor connecting the two structures. These stone ditches and foundation stones date back to the 10th century or later, indicating that they were part of the reconstruction after the original building was established without foundation stones.
Emperor Kanmu, who established Japan’s capital at Heian-kyo in 794, held a profound appreciation for the culture of the Tang Dynasty in China. Researchers suggest that major buildings of the time were constructed by placing pillars on foundation stones, a method imported from China. However, the investigation at the site indicates that, in some cases, the traditional Japanese method of not using foundation stones was also employed in Heian-kyo.
A representative from the research institute emphasized the significance of this discovery, stating, “There is great significance in finding remains from a building from the time of the establishment of the ancient capital in Kyoto. This is first-class material.”
These remarkable postholes and archaeological remains have already been carefully preserved, adding a valuable chapter to the rich history of Kyoto and Japan.