Oda Castle: What Happened to the Garden

A garden pond at Oda Castle ended under charred rice and yellow-brown earth. Excavators found that it had been deliberately filled, rather than simply left to accumulate sediment. By the castle's final phase, the eastern pond no longer functioned. Across the enclosure, a second pond remained, but in a smaller, deeper form.^[1]

The two changes were part of a larger rearrangement. A new gateway opened at the southwestern corner, protected by a separate enclosure outside the main moat. Space once devoted to a broad garden now belonged to a castle with another way in—and another position to defend.

At Oda, in present-day Tsukuba, this sequence is more informative than an imagined view of a missing tower. The ground preserves decisions about what a household needed around it: prepared approaches, places to receive people, working buildings, gardens, and defenses. Those requirements did not all disappear when the castle changed hands. They were fitted together again, sometimes by removing something that had previously seemed worth making.

Oda occupies low ground south of Mount Hōkyō, in the province historically called Hitachi. Its lords were the Oda written 小田, not the 織田 family of Oda Nobunaga. They descended from Hatta Tomoie, whose family held authority in Hitachi under the Kamakura government. Their seat developed over centuries, rather than arriving as a completed fortress at the beginning of one campaign.^[2]

Its earlier importance included receiving people whose concerns extended beyond the surrounding district. In 1338, Kitabatake Chikafusa, a leading supporter of the Southern Court in Japan's divided imperial succession, established himself here. His residence and historical writing made Oda one of that cause's eastern centers.^[3] The later ponds, however, cannot be supplied as the setting in which he composed. They belong to another stage of the ground's history.

The excavators distinguished successive working surfaces by the soil laid down during alterations. The latest lies above the earlier ones. Because digging through an old surface destroys part of what it reveals, investigation below the upper levels was deliberately limited. The sequence is better established than a complete plan of every early household.^[4]

One earlier arrangement nevertheless gives the later castle a recognizable starting point. Yellow earth had been spread to prepare a roughly rectangular compound, surrounded by a relatively narrow moat. Stones covered part of its eastern and southern ground. Substantial defensive banks belonged to a subsequent phase.

This is a useful way to understand continuity. A boundary could remain important while becoming much harder to cross. Prepared ground could continue to support residence while its surrounding works increased in scale. The later builders did not need to erase the whole compound in order to change what it could do.

The archaeological sequence accordingly gives “castle” a history within the site. It allows us to follow a residential enclosure becoming more heavily defended, without assuming that every earlier wall or ditch already answered the requirements of the final stronghold.

The outer moat did not make everything within it one undivided space. In the later castle, the principal concentration of buildings occupied a raised area in the northwest. A substantial ditch separated that area from the rest of the central enclosure. Fences or walls added further divisions.^[5]

The differences continued inside the building zone. Larger plots and concentrations of post holes and foundation stones lay toward its southern side. Smaller subdivisions, charred rice, and burned wall material characterized the north. Tsukuba's archaeological account interprets the former as the setting of substantial formal buildings and the latter as working space, including possible kitchens and stores.

That interpretation does not recover the name of every room. It does give the household an internal geography. Receiving people and sustaining the people who lived there required different arrangements. A large room could accommodate an assembly; smaller buildings and yards could support activities better kept apart from it.

The raised ground and separating ditch also made the building group a distinct destination. Someone entering the central enclosure had not necessarily entered the lord's immediate domestic or formal space. There were further edges to cross and routes to follow.

At the eastern entrance, excavation found a passage continuing toward this building group, with drainage channels along its sides. Elsewhere, a stone-covered channel passed beneath a route and was interpreted as connecting with the larger interior ditch.^[6] Movement across the compound and the passage of water through it had to coexist.

Those small arrangements help explain why a castle cannot be reduced to its barrier against an enemy. Its inhabitants also needed usable ways between one activity and another. A moat could obstruct an approach from outside; an internal channel could let water pass beneath a route that people still needed to use. Similar materials served different relationships at different points.

The garden belonged within this inhabited organization. It occupied ground beside the buildings and the approaches, rather than a separate world that began where the castle's practical life stopped.

Before the final rearrangement, the eastern pond was an irregular, elongated feature, with stones on its bottom and a shallow beach-like edge in part of its design. Nearby building traces and large quantities of small earthenware vessels led the city to interpret this as a setting for gatherings in which the garden could be viewed.^[7]

The vessels are kawarake: plain, shallow cups or dishes associated here with drinking and ceremonial meals. A photographed concentration came from a channel leading toward the pond. Their importance is not that one cup can identify a named guest. It is that a large body of ordinary serving vessels complements the evidence of buildings and prepared outdoor space.

A gathering needs more than an attractive object to look at. People have to be received, seated or otherwise accommodated, and served. The garden and vessels answer different parts of that requirement. Considered together, they make hospitality an activity that took up space and consumed materials.

Other finds suggest a different kind of attention. A small polychrome ceramic jar from Oda appears in a museum catalogue, its decorated surface carefully photographed. The site's broader assemblage includes imported ceramics and tea utensils.^[8] A decorated vessel retained for use or display and a plain vessel discarded after an occasion could belong to the same household without performing the same job.

The archaeologist Ono Masatoshi places Oda's garden within a tradition associated with provincial governors' residences. Comparing it with other excavated compounds, he emphasizes broad garden space and a relationship between buildings and ponds, rather than assuming that all warrior gardens developed in one direction. He interprets the choice of this older form at Oda as connected with the family's established standing.^[9]

The comparison helps explain why a garden might belong in the history of a ruling household, rather than being treated as its owner's private escape from government. Receiving others in an appropriate setting could be part of the household's public life. The surviving ground supports that possibility more directly than any attempt to reconstruct an unrecorded afternoon's conversation.

The western pond followed a different course. In its earlier form it spread over a broad, shallow area. Later work reduced its extent and deepened it. Stones lined the reshaped margins; the resulting pond was a more compact feature within the same side of the enclosure.^[10]

The contrast with the eastern pond matters because the changes required different work. Filling the eastern feature removed an open depression and stopped its use as a pond. Reshaping the western one retained a water feature while changing the amount and form of the space it occupied. Neither operation was merely the passive weathering of a neglected garden.

The city links the western alteration to the period in which control passed from the Oda to the Satake and proposes a practical connection with the new southwestern entrance. The earlier pond reached toward the southern bank. A smaller pond left a different relationship between garden, approach, and the edge of the enclosure.

The political chronology provides a setting for that interpretation. Oda Ujiharu lost the castle in 1569 after repeated struggles for possession. It subsequently served men connected with the Satake house. The castle continued in use until the Satake transfer to Akita in 1602.^[11]

Losing the Oda lord did not therefore leave an immediately empty site. Other occupants inherited ground already shaped for a substantial household. Their decisions concerned what to retain, alter, or add within it.

The filled eastern pond does not come with an order naming the person who had it closed. Nor does its charred rice securely date one particular attack. The physical sequence establishes something more limited: material affected by burning was used in deliberate infilling, and the final arrangement operated without that pond. Assigning every alteration to the day of a recorded battle would make the chronology more exact than the evidence permits.

The useful question is consequently not whether one lord preferred beauty and another preferred war. It is how the retained residence was reorganized. One garden feature was removed; another was made to occupy less ground; an entrance was added nearby. Together, the changes altered how the enclosure could be used.

The southwestern gateway was not simply a new opening cut through the bank. Excavation found its foundation stones and low stonework extending inward. Across the main moat lay a separate, approximately square enclosure, linked to the gateway by a wooden bridge.^[12]

This outer enclosure was an umadashi, a defensive position protecting an entrance. At Oda it was about fifty meters across, with a moat of its own. An earth bridge connected it toward another enclosure to the east. The entrance thus acquired an approach made of several parts: outer ground, crossing, intervening position, another bridge, and the main gate.

Such an arrangement addresses a problem that simply thickening a bank cannot solve. The occupants need an opening through their own defenses. People must be able to pass it without the passage becoming a direct invitation to enter every part of the residence. Defending the approach separately creates another point at which movement can be held or redirected.

The outwork's position makes the western pond's altered surroundings easier to understand. The new gate and bridge gave the southwestern edge a different role in the castle's circulation. A broad shallow garden beside that sector and a compact pond beside a new approach imposed different demands on the available ground. The city's proposed connection between the two works is spatially intelligible even where the exact construction sequence remains unresolved.

The other entrances were changing too. At the north, a wooden bridge was replaced by an earth crossing. Old bridge posts remained buried inside the later work. At the east, the entrance shifted south through successive rebuilding, while the later crossing combined an earth projection with a wooden bridge.^[13]

Those buried posts are particularly useful evidence of replacement. The change did not require every earlier component to be removed. Some timber ceased to work as a bridge support and became part of the material beneath a new crossing. What survived physically was not necessarily what continued functionally.

The surrounding moat also acquired divisions across its bottom, the arrangement called shōji-bori. These earthen ridges are interpreted as obstacles to an attacker trying to traverse the moat. At the eastern bridge, the excavators found that their layout avoided the bridge position.^[14]

Passage and obstruction were therefore designed in relation to each other. The point was not to make all movement equally difficult. The occupants still needed routes through a landscape deliberately made awkward for somebody approaching elsewhere. The garden alterations belong to this wider redistribution of usable and obstructed ground.

Oda's later moat and banks were much larger than the earlier rectangular enclosure's works. But enlargement did not proceed in only one direction. The archaeological account describes banks widening into the compound while the moat expanded outward.^[15]

That arrangement makes the cost of strengthening defenses visible without a surviving account book. Enlarging a bank inward occupies land that previously lay on its inner side. Expanding a moat outward takes additional ground beyond it. The castle can become more formidable at its edge while leaving less uncommitted space within that edge.

The household's interior was not simply preserved between two growing lines. Its building zone, passages, garden features, and entrances also changed. Work at one boundary affected what could be fitted beside it. The final plan was an accommodation of those demands, not the maximum possible amount of every desirable feature.

This gives the phrase “Oda Castle” two different continuities. One is the named seat associated with a family and its political history. The other is a body of prepared ground that later occupants could continue using after that family's control ended. The second helps explain why the castle's history outlasted the Oda's residence there.

The distinction also keeps its final decades from becoming an appendix to Ujiharu's biography. A chronicle of losses and attempted recoveries follows the dispossessed lord. The archaeological sequence follows the place that remained occupied. Each asks what continued after a defeat, but they do not follow the same subject.

Inside the final enclosure, the western pond remained a garden feature. Formal and working spaces were still differentiated. Those survivals prevent stronger defenses from being equated with the disappearance of household life. The altered castle continued to accommodate people, even as its entrances and perimeter were given new forms.

The modern archaeological park makes both ponds legible again. Its presentation places markers and recreated features above the protected remains, which lie beneath added soil. The banks, pond surfaces, and paths encountered at ground level are part of that explanatory work, not an exposed medieval landscape left untouched since the castle closed.^[16]

The eastern pond is especially instructive. It belongs to the history of the site, but not to the castle's final functioning arrangement. Seeing its form beside the later southwestern approach brings different phases into one view. The display becomes more useful when those phases are read in sequence rather than treated as a single day reconstructed outdoors.

The sequence does not produce a simple opposition between a pleasant residence and a serious fortress. Oda had required hospitality, water management, separation, and protection within the same compound. Its occupants repeatedly changed the space available to each.

The buried pond records one such change with particular clarity. Something had once been made to hold water and provide a setting beside buildings. Later, people used other material to close it. Across the ground, a smaller pond continued and a new gate required an approach. The castle's history lies in those connected decisions about what to keep working—and what to make room for next.