Nagahara Palace and Iba Palace Ruins

Two Palace Grounds That No Longer Hold a Palace

The Nagahara Goten Site and Iba Goten Site became a National Historic Site in March 2020, and a first-time visitor to either place could be forgiven for wondering what, exactly, was protected. There is no gate, no hall, no tower. At Nagahara, in Yasu City, the visible heritage is shaped earth: a low rampart about three metres high enclosing an irregular four-sided field, with a moat 16 to 20 metres wide running outside it, parts of which still hold water. At Iba, in the Notogawa district of Higashiomi City, even less stands above ground. A short run of stone retaining wall sits against a wooded slope on land that residents still call Gotenji, the palace ground.

The word goten matters here. These were not castles in the military sense, and not inns open to travellers. A goten was a compound reserved for the shogun alone. Between the opening years of the seventeenth century and 1634, the first three Tokugawa shoguns rode the road between their capital at Edo and the imperial city of Kyoto, and they needed places along the route where the head of the realm could lodge, change clothes and take a meal without sharing a roof with anyone outside his household. Nagahara and Iba were two such places.

Both sat close to the Chosenjin-kaido, a branch of the great Nakasendo highway that crossed the plain east of Lake Biwa. The road carried an unusual name. Korean diplomatic embassies, the Chosen tsushinshi, travelled it on their journeys to and from Edo, and the route kept their memory in its title. By local tradition it was also the way Ieyasu returned east after the Battle of Sekigahara in 1600, which lent it a reputation as a road of good fortune.

Why the Sites Earned National Protection

Most of what is known about the two compounds comes from two kinds of evidence that happen to agree with each other. The first is a set of drawings. The Nakai family, hereditary master carpenters to the Tokugawa, kept detailed building plans called sashizu, and copies survive for both goten. The second is the spade. Excavation at Nagahara, running since 2017, has turned up the foundation stones of structures the plans name as the Furugoten, or "old palace," the Ochin pavilion, and the Minami-no-gomon, the south gate. At Iba, archaeologists found stone alignments, footing stones and a well whose positions line up with the surviving plan of that compound. When a four-century-old drawing and a modern trench describe the same building in the same spot, the case for authenticity is hard to argue with.

That correspondence is the heart of the designation. The Agency for Cultural Affairs registered the two sites under the criterion covering remains connected with government and political history. Their value is not architectural beauty, since the architecture is gone, but documentary: together they show, on the ground, how the early Tokugawa state managed the journey to Kyoto.

That journey was itself a political act. A new shogun travelled to the imperial capital to receive his formal appointment from the court. Ieyasu, Hidetada and Iemitsu also made the trip for other reasons of state: to muster forces for the Osaka campaigns of 1614 and 1615, and to attend Emperor Go-Mizunoo's celebrated visit to Nijo Castle in 1626. Each of these processions was a display of authority, and a display needs stage management. The goten were part of the apparatus that made a shogun's movement across the country orderly, comfortable and suitably grand.

What to Look For on the Ground

Nagahara: an earthwork you can walk

Nagahara is the more rewarding of the two for a visitor who likes to read a site rather than be shown one. The honmaru, the innermost enclosure, is an uneven quadrilateral. Its western edge runs about 136 metres north to south; the southern edge measures roughly 128.5 metres east to west. Walk the perimeter and the scale of the place becomes clear. This was a substantial compound, closer to a small castle than to a country villa.

The land had a Tokugawa connection well before the palace existed. The district of Nagahara was territory granted to Ieyasu by Toyotomi Hideyoshi, and until the Battle of Sekigahara it marked the westernmost point of Ieyasu's domains. He is recorded staying at Nagahara in 1601, on his way back to Edo, and the goten took shape around that time. It was enlarged more than once. Before Iemitsu's visit of 1634, a whole new third enclosure was added to the plan.

Excavation has located the Furugoten, the Ochin pavilion, and a resting chamber, the Gokyusokujo, set in the deepest and most private part of the honmaru. The shogun's journey to Kyoto ended for good after 1634. The compound was formally dissolved in 1685, its buildings sold off at auction and dismantled, and a fire in 1705 consumed what was left. Yasu City is gradually turning the honmaru into a public archaeological park, with the western rampart conserved in place.

Iba: the trace of a kitchen

Iba is smaller and quieter, a single walled enclosure of about 90 metres north to south by 35 east to west, tucked against the western foot of Mount Kinugasa near the Notogawa settlement. It was built quickly, in 1634, expressly for Iemitsu's journey of that year. The construction was overseen by Kobori Enshu, the celebrated tea master and official works magistrate, with Nakai Yamato-no-kami as chief carpenter, of the same Nakai house whose drawings now help interpret the site.

The surviving plan shows that a large share of the compound was given over to kitchens, which fits its purpose. Iba was a place to prepare and serve a meal, not to spend the night. That role also explains its short life. Once the shoguns stopped travelling to Kyoto, a rest stop built for a single procession had no further use, and Iba was abandoned within a few decades. The stone wall on the southwest side is the clearest thing left to see, and the ground itself now serves as the festival resting-place of the local Atago Shrine.

Combining a Visit with the Surrounding Area

Nagahara sits within easy reach of Yasu Station on the JR Tokaido Line, a stop served by rapid trains and only about half an hour from Kyoto. The station area is also the gateway to Omi-Fuji, the graceful cone of Mount Mikami that rises south of the tracks, and to Mikami Shrine at its foot, whose main hall is a National Treasure of the fourteenth century. The Yasu City Museum of History and Folklore, known for its holdings related to the bronze bells, or dotaku, found in the region, makes a natural indoor companion to an afternoon spent reading earthworks.

Iba lies in the Notogawa area, a landscape of canals and reed beds along an inland lagoon of Lake Biwa. The wider Notogawa and Omihachiman district is known for its waterways and for the merchant townscape of Omihachiman, a short ride away. Travellers following the old Chosenjin-kaido can trace long stretches of the route on foot, linking the two goten sites to the larger story of how people, goods and embassies once moved across this corner of Omi Province.