Wooden Tablets Excavated from the Heijo Palace Ruins

Wooden Tablets Excavated from the Heijō Palace Site: Voices from 8th-Century Japan Whispered on Slivers of Wood

Deep beneath the grassy fields of Nara, where cherry trees now line the quiet pathways of a UNESCO World Heritage site, archaeologists have been recovering one of the most remarkable windows into 8th-century Japan ever opened. The mokkan—ink-inscribed wooden tablets excavated from the Heijō Palace Site—are tiny slivers of cypress and other woods, many no larger than a modern bookmark, yet together they form an astonishing archive of 3,184 pieces designated as a National Treasure of Japan in 2017. This was, remarkably, the very first time wooden tablets had ever received the country's highest cultural protection. For international visitors who find the austere silence of ancient ruins somehow incomplete, these tablets offer something rare: the actual handwriting, the everyday notes, the scribbled practice characters of people who lived more than 1,300 years ago.

Historical Background: A Capital Built on Paperwork

In 710 CE, Empress Genmei moved the capital of Japan from Fujiwara-kyō to a newly built city called Heijō-kyō, laid out on a grand grid modeled after Tang-dynasty Chang'an. At its northern end stood Heijō Palace—some 120 hectares of ceremonial halls, government offices, and the imperial residence, where roughly 6,500 officials worked daily in service of a fledgling centralized state. For just over seven decades, this palace was the administrative heart of Japan, until the court relocated to Nagaoka-kyō in 784 and finally to Heian-kyō (modern Kyoto) in 794.

What happened next is crucial to the story of the mokkan. After the move, Heijō-kyō was gradually abandoned, and the palace grounds slowly turned back into rice fields and farmland. The buildings rotted, the monuments collapsed, and for over a thousand years the site lay largely undisturbed beneath the soil. Serious excavation began in 1959 under what became the Nara National Research Institute for Cultural Properties, and ever since then, archaeologists have been pulling up extraordinary finds—including the wooden tablets that officials had once tossed into pits, ditches, and drainage channels when they were no longer needed. Preserved by the waterlogged, oxygen-poor soil, the ink on many of these discards remained as legible as if written yesterday.

Why These Wooden Tablets Became a National Treasure

The designation in September 2017 was a landmark moment. Before that date, four separate groups of Heijō Palace mokkan had already been recognized as Important Cultural Properties, together totaling 2,875 pieces. The 2017 decision consolidated those four groups and added 309 previously undesignated tablets, producing a single unified treasure of 3,184 pieces. No wooden tablet had ever before been elevated to National Treasure status in Japan.

The reasoning behind the designation rests on a simple but profound point: official histories like the Rikkokushi (the Six National Histories) were compiled long after the events they describe, edited by court officials with political agendas. Mokkan, by contrast, are working documents—scribbled, crumpled, discarded—that no one ever intended posterity to read. They cannot be altered or retouched because they come directly from the ground. They record the ordinary business of government: tax receipts, meal orders, guard duty rosters, and even the idle doodles of clerks. In short, they show Nara-period Japan as it actually was, not as the court chose to remember it.

There is also a linguistic dimension. The tablets capture a pivotal moment when the Japanese were still learning to adapt Chinese characters to their own spoken language. The scripts vary wildly from one tablet to the next—formal reisho (clerical), flowing sōsho (cursive), and upright kaisho (standard)—showing a culture in the act of finding its written voice.

What the Tablets Contain: Four Windows into the Nara Court

Scholars sort the 3,184 tablets into four broad categories, each offering its own kind of glimpse into palace life.

Highlights and Must-See Features

The headline discovery came in 1961 from a refuse pit known by its archaeological code SK820, located in the administrative zone north of the inner palace. The tablets from SK820 date to roughly 745–747 CE, the years when Emperor Shōmu returned to Heijō Palace after five years of court wandering, and when construction of the Great Buddha at Tōdai-ji was just beginning in the eastern suburbs. SK820 was the first place in Japan where a single group of more than one thousand mokkan was ever recovered, and the find effectively launched the modern field of wooden-tablet studies.

Other celebrated pieces include a large tablet that functioned as a travel permit—essentially an ancient passport used by officials passing between provinces—and a collection of tags written by the brewing office (Miki-no-tsukasa) cataloguing the sake served at court banquets. Tablets found near the Daizen-shiki, the imperial kitchen office, record the daily menus prepared for high-ranking officials, while tablets from the Naizen-shi, which served the emperor's personal table, list delicacies sent up from fishing villages along the Seto Inland Sea.

The tablets are housed at the Heijō Palace Site Museum, located on the northwest edge of the Heijō Palace site. Because wooden artifacts are fragile and sensitive to light, the actual originals are rotated for public display primarily during the annual autumn special exhibition "Underground Shōsōin" (Chika no Shōsōin-ten), timed to coincide with the famous Shōsōin Exhibition held at the Nara National Museum. Replicas, photographs, and detailed explanatory panels remain on view year-round in the permanent galleries.

Visitor Information

The Heijō Palace Site Museum is free to enter and welcomes international visitors throughout the year. The museum sits within the vast Heijō Palace Site Historical Park, which is itself a component of the "Historic Monuments of Ancient Nara" UNESCO World Heritage Site inscribed in 1998. From Kintetsu Yamato-Saidaiji Station—the closest train station and a key stop on the line connecting Osaka and Nara—the museum is approximately a five-minute walk east from the north exit.

Visitors intending to see the actual designated mokkan should aim their trip at the autumn special exhibition, typically held from mid-October through late November, with the tablets rotated across three sub-periods to limit light exposure. Outside that window, the permanent displays still give a rich introduction to the finds, supplemented by full-scale reconstructions of Nara-period offices and palace interiors.

A visit to the museum pairs naturally with a walk through the adjacent palace grounds, where the reconstructed Suzakumon Gate, the First Daigokuden (Great Audience Hall), and the East Palace Garden bring the scale of the ancient capital vividly to life.

Surrounding Attractions

The Heijō Palace Site sits in the northwest quadrant of modern Nara City, and the whole district is dense with remarkable destinations. Within walking or short-bus distance are Tōshōdai-ji, founded by the Chinese monk Ganjin in 759 and home to a main hall that incorporates a relocated building from Heijō Palace itself, and Yakushi-ji, whose East Pagoda is one of the few structures in Japan to have stood continuously since the 8th century. Saidai-ji Temple, once among the most important monasteries of the Nara period, sits just west of the palace site.

A little further east lies the more famous cluster of Nara heritage: Tōdai-ji with its towering bronze Buddha, Kōfuku-ji, Kasuga Taisha, and the deer-filled Nara Park. Each autumn the Nara National Museum hosts the Shōsōin Exhibition, which displays treasures from the 8th-century imperial repository—a natural pairing with a visit to the mokkan exhibition, since together the two offer a nearly unmatched view of Nara-period court life.