The Nakazu Higashihara Site: A Medieval Port Town on Japan's Western Coast
On the western edge of Shimane Prefecture, near the mouth of the Masuda River, lies one of Japan's most fascinating medieval discoveries. The Nakazu Higashihara Site (中須東原遺跡) is the buried remains of a bustling international port town that thrived for nearly five centuries, from the 12th to the 17th, exchanging goods and culture with China, Korea, and even Southeast Asia. Unlike the famous trading ports of Sakai or Hakata, Nakazu has remained off the standard tourist trail—yet its archaeological treasures and historical significance place it among the most important medieval port sites ever excavated in Japan.
For travellers seeking an authentic, lesser-known dimension of Japanese history, Nakazu offers something rare: the chance to stand on the very ground where ships from across East Asia once unloaded their cargoes of porcelain, silk, and spices, in a town whose wooden buildings, smithies, and stone-paved wharves have been brought back to light by decades of careful excavation.
A Lagoon Town at the Edge of the Japan Sea
To understand why Nakazu mattered, picture the medieval Masuda plain. The Takatsu and Masuda Rivers met near the coast, and a long sandbar had grown between them and the open sea, creating a sheltered lagoon known as a sekiko. This natural harbour shielded ships from the harsh winds and waves of the Japan Sea, making it an ideal anchorage for vessels travelling along the coast or crossing to the continent.
The town that grew here was no accident. The rivers connected the port to the densely forested Chugoku Mountains inland, a region rich in high-grade timber—especially around Hikimi—and in metals from the Tsumo mine upstream of the Masuda River. These goods could be floated down by raft and loaded onto ships bound for distant markets. In return, foreign vessels brought ceramics, coins, and luxury wares from across East Asia.
The site itself occupies the back side of the sand dunes on the left bank of the Masuda River, covering roughly 42,000 square metres. Settlement began here as early as the 12th century, but the town reached its peak between the late 14th and 16th centuries, the very era when the Masuda clan ruled the region as one of the most influential warrior families of western Iwami Province.
What the Earth Revealed: The Excavations
Modern excavations at Nakazu Higashihara began in connection with a land-readjustment project on the northern part of the Masuda River's left bank. What archaeologists found exceeded all expectations. Along the former edge of the lagoon, they uncovered an enormous gravel-paved structure stretching about 40 metres long and up to 10 metres wide—almost certainly the remains of a loading and unloading wharf where ships' cargoes were transferred to land.
Behind the wharf, the buried town came into view: rows of post-hole buildings, smithy furnaces with their fragments of iron slag, dedicated dumping pits for the waste of metalworking, graves, and a grid of roads. By comparing the positions of these roads with early Meiji-era pictorial maps and with finds from the adjacent Nakazu Nishihara Site, researchers concluded that Nakazu was laid out as a planned, rectangular street network—essentially a small medieval city.
The artefacts told an even richer story. Trade ceramics dominated the finds. Roughly eighty percent were Chinese wares, including rare examples such as Yuan-dynasty large bowls with underglaze iron and lapis decoration. About twelve percent were Korean ceramics, among them inlaid celadons and the distinctive Joseon-period buncheong stoneware. Even more striking were the Thai and Vietnamese pieces, evidence that goods from Southeast Asia reached this small Shimane lagoon by the 15th century.
Why It Was Designated a National Historic Site
In November 2013, Japan's Council for Cultural Affairs recommended that Nakazu Higashihara be designated a National Historic Site, and on 18 March 2014 the designation was formalised. The decision rested on several remarkable qualities.
First, Nakazu is one of the very few medieval port sites in Japan whose overall structure has been preserved well enough to reconstruct in detail. Most ports of this period have either been lost to modern development or are known only through fragmentary remains; here, the wharf, the workshops, and the street plan all survived.
Second, the site can be cross-referenced with an extraordinary archive: the Masuda Family Documents (Masuda-ke Monjo), a body of medieval records left by the local lords. These papers show that the Masuda clan was deeply involved in maritime transport and trade, and they sometimes mention specific places and activities that match the archaeological finds. A 1376 entry, for example, refers to a "blacksmith myo" at Onakazu—precisely the kind of metalworking shown by the smithy remains at the site. The combination of written and excavated evidence is unusually complete, allowing scholars to trace not only how the port grew but also what was traded and by whom.
To preserve the discovery, the city of Masuda revised its land-readjustment plan to keep the buried town intact. Today the site is managed by the city as a protected national monument, with the Nakazu Nishihara Site immediately to the west forming part of the same medieval harbour complex.
Highlights for Visitors
Nakazu Higashihara is, by its nature, an archaeological reserve rather than a reconstructed theme park. Much of the site lies preserved beneath the surface, with interpretive signage guiding visitors through its layout. This is part of its quiet appeal: those who come are walking the same ground where Korean potters' bowls and Thai jars once changed hands, with the modern town gently overlying the medieval one.
A short stroll northwest brings you to Fukuoji Temple, a Jodo-sect temple whose grounds preserve a wealth of medieval stone monuments—including a graceful thirteen-tiered granite pagoda from the Nanboku-cho period and a five-ringed stone stupa dated 1330. These works, contemporary with the height of the port, give a tangible sense of the religious life that ran alongside Nakazu's commercial bustle.
Pairing the site with a panoramic view of the Masuda plain helps the story click into place. From a higher vantage point, you can trace the line where the lagoon once curled inland and imagine the masts of ocean-going ships standing where rice fields now lie.
Around Nakazu: Exploring Medieval Masuda
Nakazu Higashihara is one node in a constellation of cultural properties that together form the Japan Heritage story "Medieval Japan's Masterpiece: Tasting Masuda." Anyone interested in this period should set aside at least a full day to explore the wider network.
The Masuda Clan Residence and Castle Ruins (Masuda-shi Joukan Ato), themselves a National Historic Site, preserve the political heart of the territory that ran the port. Nearby, the temples of Iko-ji and Manpuku-ji each contain a celebrated garden attributed to the painter-monk Sesshu Toyo (1420–1506), who spent his later years in Masuda under the patronage of the Masuda lords. Sesshu's grave is also in the city, at the Otokichi Daikian site.
For travellers who enjoy connecting sites to landscape, the Imaichi Site offers another medieval port settlement of similar character, while the broad Masuda plain still bears traces of the old lagoon. The Masuda City Museum of History and Folklore is a useful first stop for context, displaying excavated artefacts and explanatory panels that bring the buried town to life.
- 📍 Plan Your Visit to Shimane
- Find tours, activities & transport passes near Nakasu Higashihara Ruins
- [ Izumo Taisha Shrine & Adachi Museum Gardens ]
Q&A
- What kind of site is Nakazu Higashihara, and what makes it special?
- It is the buried remains of a medieval international port town that flourished roughly between the 12th and 17th centuries, with its peak from the 14th to 16th. What makes it special is that the wharf, workshops, street grid, and graves have all survived together, and the finds can be cross-referenced with the surviving Masuda Family Documents.
- When was it designated a National Historic Site?
- It was designated on 18 March 2014, following a recommendation from the Council for Cultural Affairs in November 2013.
- What sort of objects were excavated there?
- Excavations recovered large quantities of trade ceramics—roughly 80% Chinese, 12% Korean, plus pieces from Thailand and Vietnam—along with iron slag, blacksmithing tools, coins, and everyday domestic wares. The variety shows just how connected this small lagoon town was to the wider East Asian maritime world.
- Is there a visitor centre or museum on site?
- The site itself is a preserved open area with explanatory signage rather than a built-up tourist facility. For more in-depth information, exhibits, and excavated objects, visitors should head to the Masuda City Museum of History and Folklore or pick up the city's illustrated pamphlet on Nakazu Higashihara, available from the Masuda City Board of Education's Cultural Properties Section.
- How is the site related to the Masuda clan?
- The Masuda clan was the leading warrior family of the region during the medieval period and is thought to have been deeply involved in the port's operation. Their own documents, the Masuda-ke Monjo, attest to their engagement in water transport and trade, which fits closely with the archaeological evidence from Nakazu.
Basic Information
| Name | Nakazu Higashihara Site (中須東原遺跡 / Nakazu Higashihara Iseki) |
|---|---|
| Designation | National Historic Site (designated 18 March 2014) |
| Site type | Medieval port settlement |
| Period | 12th–17th centuries (peak: 14th–16th centuries) |
| Approximate area | About 42,000 m² |
| Location | Nakazu-cho, Masuda City, Shimane Prefecture, Japan |
| Management | Masuda City (designated as managing body in March 2015) |
| Nearest station / airport | JR Masuda Station; Hagi-Iwami Airport |
| Inquiries | Masuda City Board of Education, Cultural Properties Section (TEL: 0856-31-0623) |
References
- Nakazu Higashihara Site — Cultural Heritage Online (Agency for Cultural Affairs)
- https://online.bunka.go.jp/heritages/detail/271586
- National Designated Cultural Properties Database — Nakazu Higashihara Site
- https://kunishitei.bunka.go.jp/heritage/detail/401/00003840
- History and Culture — Masuda City
- https://www.city.masuda.lg.jp/soshikikarasagasu/kyoikuiinkai/bunkazaika/3/3149.html
- Japan Heritage Portal — "Medieval Japan's Masterpiece: Tasting Masuda"
- https://japan-heritage.bunka.go.jp/ja/stories/story100/
- Children's Pamphlet "Discovering Masuda's History: Nakazu Higashihara Site" — Masuda City
- https://www.city.masuda.lg.jp/soshikikarasagasu/kyoikuiinkai/bunkazaika/8/kankoubutu/3132.html
- Nakazu Higashihara Site — Comprehensive Database of Archaeological Site Reports, Japan
- https://sitereports.nabunken.go.jp/en/16555
Last verified: 2026.05.14