鳥羽城 · Toba-jo
Kuki Yoshitaka's sea-castle — where Japan's greatest naval commander built his base above the iron warships that changed maritime warfare.
#154 — Continued 100 CastlesEntirely free to visit. The castle ruins are on a public hill park. The nearby Toba City Museum charges admission but is not the castle itself.
Toba Castle is for visitors interested in the naval dimension of Sengoku history — a topic almost completely absent from the major castle circuit. The ruins themselves are modest, but the setting on Toba Bay with the Ise-Shima island chains visible below is evocative of Kuki's maritime world. The castle is best visited as part of a Toba day that includes Mikimoto Pearl Island and the wider Ise-Shima area. Toba is an hour from Nagoya by Kintetsu limited express.
Toba Castle was built by Kuki Yoshitaka, the samurai who commanded Oda Nobunaga's navy and invented the iron warship (atakebune). His fleet destroyed the combined naval forces of the Mori clan and the warrior monks of the Honganji temple at the Battle of Kizugawaguchi (1578) — a victory that sealed Nobunaga's control of Osaka Bay. Kuki was the foremost naval strategist of the Sengoku period, and Toba was his home base.
Toba Castle is categorized as a 'mizujiro' (water castle) — designed primarily for naval warfare and sea-lane control rather than land-based defense. Built on a peninsula hill directly overlooking Toba Bay and the Ise-Shima island chains, the castle's strategic value was control of the Ise Bay shipping routes — the maritime lifeline of central Japan. The castle's sea-facing walls served as a launching platform for the Kuki naval fleet.
Toba sits at the entrance to Ise-Shima — the peninsula chain of islands and harbors that includes the Grand Shrine of Ise (Ise Jingu), Japan's most sacred Shinto site. Control of Toba meant control of the approach routes to Ise itself, giving the castle a religious-political significance beyond its military value. The Toba area today is Mie's busiest tourist hub, with Mikimoto Pearl Island and Toba Aquarium drawing visitors alongside the castle ruins.
Visitor Tip
Toba Castle ruins are best visited as a complement to the broader Toba sightseeing area. The ruins themselves are modest — scattered stone walls and earthwork platforms on a wooded hill. The value is the setting and the Kuki Yoshitaka connection. The hilltop gives good views over Toba Bay and the island chains beyond. Combine with Mikimoto Pearl Island and Toba Aquarium for a full Toba day.
mizujiro
Sea castle — built on a peninsula hill directly overlooking Toba Bay, with water access on multiple sides and designed for naval operations rather than purely land-based defense
renkaku
Compound style — terraced compounds on the peninsula hill, with the main compound at the summit overlooking the bay
Ruins — no keep survives. Stone wall sections and terraced compound platforms remain on the hill, with the best-preserved walls on the bay-facing slopes.
nozurazumi — Natural stone stacking — Edo-period ishigaki sections survive on the hill, particularly on the water-facing slopes
Surviving stone wall sections are scattered across the castle hill, with the best-preserved ishigaki on the bay-facing slope. The walls are modest in scale compared to major land castles — their primary function was to support the castle's role as a naval command base rather than to withstand siege.
Peninsula Sea Approach
Toba Castle's peninsula position meant any land-based assault had to approach along the narrow neck connecting the castle hill to the mainland, while sea-based assault faced the castle's walls with the high ground above. The Kuki navy could contest any seaborne approach.
Naval Fleet Integration
The castle's primary defense was its naval fleet — Kuki's iron warships anchored in the bay below served as a mobile defensive screen that any attacker had to defeat before land assault was viable. The castle and fleet functioned as an integrated military system.
The Deadliest Gate in Japan
The attacking force crosses the moat and approaches the outer gate. Defenders hold fire, allowing the enemy to commit.
Historical Context — Toba Castle
Attacking Toba Castle required either defeating the Kuki naval fleet on Toba Bay first (enormously difficult given Kuki's reputation and his iron warships), or assaulting overland along the narrow peninsula neck under fire from the elevated compounds. Any force that managed both approaches still faced the hilltop position. In practice, the castle's greatest protection was the reputation and firepower of the Kuki fleet — no land army was keen to assault while warships controlled the coastal flanks.
Kuki Yoshitaka, having served as Oda Nobunaga's and then Toyotomi Hideyoshi's preeminent naval commander, constructs Toba Castle on the peninsula overlooking Toba Bay. The castle serves as his administrative seat and the base of the Kuki maritime domain.
Kuki leads the Japanese naval forces in Korea during Hideyoshi's second invasion (Keicho no eki). His naval experience at battles against the Korean admiral Yi Sun-sin shapes his understanding of iron warship limitations — lessons he had already applied at Kizugawaguchi.
At the Battle of Sekigahara, Kuki Yoshitaka's son Moritaka sides with the Eastern (Tokugawa) forces while Yoshitaka supports the Western. Yoshitaka, on the losing side, commits seppuku. Moritaka is confirmed in control of the Toba domain.
The Kuki clan is transferred away from Toba by the Tokugawa government, and a succession of different domain lords holds Toba through the remaining Edo period. The castle continues as a functional administrative center without major modification.
The Battle of Toba-Fushimi — the opening military engagement of the Boshin War between Tokugawa and imperial forces — is fought at Toba, though not at the castle itself. The battle name 'Toba-Fushimi' is one of the most famous in Meiji Restoration history.
Kuki Yoshitaka appears in multiple NHK taiga dramas about Oda Nobunaga, usually in scenes depicting the naval campaigns on Osaka Bay. His distinctive iron warships are a visually compelling element in historical drama production.
Year-round. Spring and autumn for most comfortable temperatures. The waterfront setting is appealing in any season.
30 to 45 minutes for the ruins; full day for Toba as a whole
Look out from the castle hilltop toward the island chains of Ise-Shima and try to visualize Kuki's iron warships anchored in the bay below — the same waters his fleet patrolled 400 years ago. The Toba Aquarium, one of Japan's largest, is immediately below the castle hill and makes a natural half-day addition, especially for visiting families.
Free Entry
Entirely free to visit. The castle ruins are on a public hill park. The nearby Toba City Museum charges admission but is not the castle itself.
Open at all times. The ruins are on a public park hill — no gates or restrictions.
伊賀上野城 · Iga-Ueno-jo
📍 Mie — Kansai
Japan's tallest stone walls, a ninja museum next door, and the ghost of a seven-story tower that a typhoon stole — Iga-Ueno is one of Japan's most undervisited castle surprises.
名古屋城 · Nagoya-jo
📍 Aichi — Chubu
Nagoya Castle is mid-renovation — visit now for the stunning reconstructed palace, return in a few years for the completed wooden tower.
The nearest station is Toba Station (Kintetsu Shima Line / JR Sangu Line). It is approximately a 10-minute walk from the station. Parking: Street parking and paid lots available near the castle hill. Limited but adequate for the volume of visitors this site receives. Accessible with a JR Pass.
Toba Castle is free to enter. Entirely free to visit. The castle ruins are on a public hill park. The nearby Toba City Museum charges admission but is not the castle itself.
Toba Castle is for visitors interested in the naval dimension of Sengoku history — a topic almost completely absent from the major castle circuit. The ruins themselves are modest, but the setting on Toba Bay with the Ise-Shima island chains visible below is evocative of Kuki's maritime world. The castle is best visited as part of a Toba day that includes Mikimoto Pearl Island and the wider Ise-Shima area. Toba is an hour from Nagoya by Kintetsu limited express.
Toba Castle is open 00:00 – 23:59 . Open at all times. The ruins are on a public park hill — no gates or restrictions.
Plan on spending 30 to 45 minutes for the ruins; full day for Toba as a whole at Toba Castle. Look out from the castle hilltop toward the island chains of Ise-Shima and try to visualize Kuki's iron warships anchored in the bay below — the same waters his fleet patrolled 400 years ago. The Toba Aquarium, one of Japan's largest, is immediately below the castle hill and makes a natural half-day addition, especially for visiting families.