Omizo Waterfront Scenery

Ōmizo: A Castle Town Built Around Water on Lake Biwa's Western Shore

Step off the train at Ōmi-Takashima Station and walk about 150 metres to the southeast, and you reach a low, tree-covered mound ringed by rough stone walls. This is the keep platform of Ōmizo Castle, raised in 1578 on the northwest shore of Lake Biwa. The castle is gone, but the shape of the town it anchored is still legible in the street grid, the water channels that run between the houses, and the reed-fringed inner lake just to the southeast.

The full landscape stretches across roughly 1,384 hectares of the southern part of Takashima City, in Shiga Prefecture. It sits in a narrow band between the Hira mountain range and the lake, and almost everything here is organised around water: the open water of Lake Biwa, the quiet inner lake called Otomegaike, the wells and channels of the old town, and the spring water that flows down from the western foothills.

A Crossroads on the Lake

People were using this stretch of shore long before any castle stood here. In ancient times the Hokurikudō, one of the highways that linked the capital region with the provinces to the north, passed through, and historians identify Ōmizo with the road's Mio station and with Katsuno-tsu, a major harbour for boat traffic on Lake Biwa. Goods and travellers moving between the Sea of Japan coast and the old capitals at Nara and Kyoto came this way, and the town grew up as a transfer point between road and water.

That long history of movement left its mark. The settlement runs in a line along the old highway, a layout known in Japanese as a row village, and the pattern survives despite later upheavals: steamships arriving in the early Meiji period, then the railway laid down in the early twentieth century. The way the town is strung along the road still reflects its origins as a place built for passing through.

The Water Castle and the Domain That Followed

In 1578 Oda Nobuzumi, a nephew of the warlord Oda Nobunaga, moved his base here from nearby Shinjō and built Ōmizo Castle. What made it distinctive was its use of water. Otomegaike, the inner lake separated from Lake Biwa by a sandbar, served as the outer moat, while channels and a river formed the inner defences. A castle of this kind, set into the water rather than on a hilltop, was called a water castle, and Ōmizo also went by the poetic name Kōkō Castle. Local tradition credits the design of the fortifications to Akechi Mitsuhide, though this is not firmly documented.

Nobuzumi did not hold the castle for long. After the turmoil of the late sixteenth century the site passed through several hands before Wakebe Mitsunobu arrived in the early Edo period. From then on the Wakebe family governed the Ōmizo domain from a fortified residence here, rather than a full castle, for twelve generations until the Meiji Restoration ended samurai rule. As the castle's military role faded, the town settled into the role of a quiet domain seat.

Why It Was Designated

In January 2015 the Agency for Cultural Affairs selected the Waterside Landscape of Ōmizo as an Important Cultural Landscape, the third such designation within Takashima City. The category, created in 2005, protects scenery shaped by the interaction of people and their environment over time. Rather than freezing a place exactly as it is, the system aims for what is called dynamic preservation, keeping a living landscape working while allowing it to adapt.

What earned Ōmizo the designation is the way the spatial structure of a late-medieval and early-modern castle town survives intact, together with the water systems that the residents still use. The site shows how generations made their living by drawing skillfully on lake water, the inner lake, and mountain springs. The whole arrangement, from the castle layout to the household water supply, remains visible in the present-day town.

What to Look For When You Visit

Start at the keep platform of the castle. Its stone walls are built in the nozura-zumi style, using natural, roughly shaped stones stacked without dressing, and the corners use the interlocking sangi-zumi technique. These walls are among the few tangible remains of the castle, and the rough surfaces photograph well in the afternoon light, when the southern face catches the sun.

From the platform the ground falls away toward Otomegaike to the southeast. The reedy inner lake that once formed the outer moat is still here, and hornwort and wild rice grow thick across its surface. For centuries these water plants were harvested for fertiliser and animal feed, with some plots privately held and others worked in common, the cutting rights settled each year by auction. It is an unusually clear record of how a lakeside community shared a common resource.

In the old town itself, watch the water. An Edo-period system of pipes and channels still delivers spring and well water to homes. One association draws from a source at the same elevation as the houses and runs buried pipes to each door; another, fed from a source in the western foothills, uses small distribution structures called tachiagari to split the flow. Down in the Uchioroshi district, on the sandbar between the inner lake and Lake Biwa, residents historically worked as boatmen and fishers in peacetime and formed a naval force in war. They built stone walls along the lake side of the settlement to hold back high waves and flooding, and those walls still line the shore.

Around the Town

The compact scale of Ōmizo makes it easy to explore on foot in a few hours. The restored main gate of the Wakebe residence, the Sōmon, is the only building of the old domain compound still standing. It reopened in April 2024 as a visitor centre and small exhibition space, and a roughly fifteen-minute CG film reconstructs how the water castle once looked. The centre also hands out castle stamps popular with history enthusiasts. Nearby, the Takashima Village area gathers craft workshops and cafés in renovated old buildings, and the lakeside Ōmizo harbour and Wakebe Shrine are both within a short walk. Bringing a camera and good walking shoes, and allowing time to follow the water channels rather than just the main streets, is the best way to understand how the place fits together.