• Stone marker: A marker identifies this as the site of Oda Nobutada's mansion.
• Tokutomi Sohō's poem stone: A stone inscribed with a classical Chinese-style poem about Mt. Azuchi stands nearby and is worth a look on the same stop.
• A crossroads location: The site sits at the junction of the Otemichi approach road and the Dodobashiguchi path — a strategically significant spot.

Quick visit: about 5 min / Unhurried: about 15 min

🗺 Address: Shimotoyoura, Azuchi-cho, Omihachiman, Shiga Prefecture
🚶 Access: You'll reach it as you continue from the Otemichi area toward the Tenshudai.

Rating: Historical value ★★ / Visual appeal ★ / Experience value ★

Azuchi Castle Ruins archaeological excavation report

• The Honnoji Incident: Nobutada had already been handed leadership of the Oda clan. When he learned his father was under attack, he moved to Nijō Palace and fought Akechi's forces there before taking his own life — dying separately from Nobunaga, and never getting the chance to lead the clan into the future.
• The heir apparent: As Nobunaga's eldest son, Nobutada carried the full weight of his father's expectations for the Oda clan's future.

• Stone wall remains: Stone walls marking the mansion's boundary survive, giving a faint sense of its original layout.
• Position relative to Kuroganemon Gate: Given its position just before the Kuroganemon Gate, it's easy to imagine that Ranmaru may have been trusted enough by Nobunaga to be given a role close to the castle's core.

Quick visit: about 5 min / Unhurried: about 15 min

🗺 Address: Shimotoyoura, Azuchi-cho, Omihachiman, Shiga Prefecture
🚶 Access: Climbing from the Oda Nobutada mansion site toward the Tenshudai, it appears on the left.

Rating: Historical value ★★ / Visual appeal ★ / Experience value ★

• A mark of trust: Given its position just before the Kuroganemon Gate, it's easy to imagine that Ranmaru may have been trusted enough by Nobunaga to be given a role close to the castle's core.
• The Honnoji Incident: Mori Ranmaru served as one of Nobunaga's closest attendants and died alongside his lord in the Honnoji Incident.

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• Stone markers for Oda Nobuzumi and Mori Ranmaru: Two stone markers stand together among the trees, indicating the locations traditionally associated with each man's residence. No remains showing the actual shape or layout of either building survive.
• A cluster of mansion sites along the path to Kuroganemon Gate: Along the route toward the Shukakubu are several sites traditionally linked to Oda-clan relatives and retainers, and this Nobuzumi site is one of them.

Viewing the markers themselves takes only a few minutes. There's no official visit-time estimate for this spot alone, but it's best seen together with the Mori Ranmaru mansion site and Kuroganemon Gate.

🗺 Address: Shimotoyoura, Azuchi-cho, Omihachiman, Shiga Prefecture (within the Azuchi Castle ruins)
🚶 Access: The marker stands at the same spot as the Mori Ranmaru mansion site.

Rating: Historical value ★★ / Visual appeal ★ / Experience value ★

• Son of Nobunaga's executed brother: Nobuzumi was the son of Oda Nobukatsu (Nobuyuki), the younger brother Nobunaga had put to death. He went on to serve the Oda clan and later became lord of Omizu Castle.
• The "den" (traditional) label: The word "den" (伝) in the site's name signals that this is not confirmed with certainty as Nobuzumi's actual mansion site.
• Ties to Akechi Mitsuhide: Nobuzumi was Akechi Mitsuhide's son-in-law. Because of that connection, he was suspected of conspiring with Mitsuhide after the Honnoji Incident — historians generally believe he was killed within days on the orders of his cousin Oda Nobutaka mainly because of that marriage tie, with little solid evidence that he was actually involved in the plot.
• Nobuzumi in the 2026 Taiga drama: Azuchi Castle sits within the filming-location world of NHK's 2026 year-long historical drama Toyotomi Brothers! ("Toyotomi Kyōdai!") — one of Japan's annual flagship historical dramas, watched by a broad national audience. In it, actor Ogata Atsushi plays Oda Nobuzumi, portrayed as a man torn by conflicting loyalties as Nobunaga's nephew.

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• Massive stone walls: The stone walls around Kuroganemon Gate use unusually large stones, signaling both defensive strength and status.
• Masugata koguchi layout: The passage makes two right-angle turns — a structure where the path bends twice, slowing down any intruder's movement and making them easier to attack from the surrounding walls.
• Gold-leafed roof tiles: Excavations near the gate also turned up gold-leafed tiles bearing chrysanthemum and paulownia crests.

Quick visit: about 5 min / Unhurried: about 15 min

🗺 Address: Shimotoyoura, Azuchi-cho, Omihachiman, Shiga Prefecture
🚶 Access: You'll reach it heading from the Mori Ranmaru mansion site toward the Tenshudai.

Rating: Historical value ★★★ / Visual appeal ★★★ / Experience value ★★

Azuchi Castle Ruins archaeological excavation report (1993 survey)

• Discovery of the gold-leafed tiles: The 1993 excavation showed that Kuroganemon Gate burned along with the castle tower, and the burned tiles recovered included gold-leafed examples bearing chrysanthemum and paulownia crests.
• Why "Kurogane" (Black Iron): "Kurogane" is an old word for iron. The name suggests the gate may have been a heavy structure making extensive use of iron plating and fittings, but the gate itself no longer survives, so its exact appearance remains uncertain.

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• Memorial pagoda: A stone pagoda dedicated to Nobukatsu and four generations of his descendants.
• Surrounding stone walls: Stone walls nearby hint at the former presence of a samurai residence.

Quick visit: about 5 min / Unhurried: about 15 min

🗺 Address: Shimotoyoura, Azuchi-cho, Omihachiman, Shiga Prefecture
🚶 Access: From Kuroganemon Gate, head toward the Tenshudai and turn onto the small path on the left.

Rating: Historical value ★★ / Visual appeal ★ / Experience value ★

• The Oda clan's survival: Nobukatsu is one of the few figures who retained his standing as a feudal lord after Nobunaga's death, carrying the family's bloodline all the way into the Edo period.
• The traditional Hasegawa Hidekazu mansion site: The memorial pagoda stands on what's said to be the former mansion site of Hasegawa Hidekazu, giving the land itself a layered history.

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• Surviving stone walls: Sections of period stone walls remain, giving a sense of Sengoku-era castle-building techniques.
• The long, narrow terrain: The distinctive shape of an obikuruwa is fun to appreciate while thinking through the castle's defensive strategy.

Quick visit: about 5 min / Unhurried: about 15 min

🗺 Address: Shimotoyoura, Azuchi-cho, Omihachiman, Shiga Prefecture
🚶 Access: From the Oda Nobukatsu memorial pagoda, return to the main path and continue toward the Tenshudai.

Rating: Historical value ★★ / Visual appeal ★ / Experience value ★

• A multi-purpose enclosure: An obikuruwa wraps around a major enclosure, serving not just as a defensive line but also as a route for moving through the castle and transporting supplies.

• The stone itself: Carved with an image of Buddha's footprints, this is a valuable relic from the medieval period.
• A symbol of repurposing: This stone stands as evidence that Nobunaga's builders repurposed even Buddhist-related stones as raw construction material.

See panoramic photos here (senior retainers' mansions and Niō-mon Gate)

Quick visit: about 5 min / Unhurried: about 15 min

🗺 Address: Shimotoyoura, Azuchi-cho, Omihachiman, Shiga Prefecture
🚶 Access: From the Ninomaru South Perimeter Enclosure Ruins, continue along the main path toward the Tenshudai.

Rating: Historical value ★★★ / Visual appeal ★ / Experience value ★★

• An object of worship that predates Buddhist statues: A bussokuseki was an object of worship before Buddhist statues existed; in Japan, the oldest known example is at Yakushi-ji Temple in Nara.
• A culture of repurposed stone: Beyond the bussokuseki, Buddhist statues and five-ring memorial stones were also repurposed into Azuchi Castle's stone walls and steps, offering a glimpse of how building materials were gathered during construction.

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• Nobunaga's Mausoleum: This is where Nobunaga's personal effects are said to be buried. Visitors are free to pay their respects.
• Surrounding stone walls: Period stone walls remain around the mausoleum.
• Nobunaga-ki: Every June 2, a memorial service called "Nobunaga-ki" is held at Sōken-ji Temple.

Quick visit: about 5 min / Unhurried: about 20 min

🗺 Address: Shimotoyoura, Azuchi-cho, Omihachiman, Shiga Prefecture
🚶 Access: From the Bussokuseki, continue toward the Tenshudai and turn onto the small path on the left.

Rating: Historical value ★★★ / Visual appeal ★★ / Experience value ★★★

• The first-anniversary service: The first-anniversary memorial was hosted by Hashiba Hideyoshi on June 2, 1583, attended by members of the Oda clan and its retainers.
• Built by Hideyoshi: The mausoleum was built by Hashiba Hideyoshi, who is said to have buried Nobunaga's personal effects here.

• Nobunaga's Mausoleum: The mausoleum Hideyoshi built stands within this area.
• Surviving stone walls: Period stone walls remain around the Ninomaru ruins.

Quick visit: about 5 min / Unhurried: about 15 min

🗺 Address: Shimotoyoura, Azuchi-cho, Omihachiman, Shiga Prefecture
🚶 Access: Located at the same spot as Nobunaga's Mausoleum.

Rating: Historical value ★★★ / Visual appeal ★★ / Experience value ★★

• The castle's core: Now called the "Traditional Ninomaru Site," this area's closeness to the Tenshudai and the Traditional Honmaru Site suggests it was an important part of the castle's core.

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• 119 building pillar bases: Pillar bases arranged in a grid pattern let you directly sense the scale of the original building.
• The vastness of the "Thousand-Mat Hall": True to its nickname, an astonishingly wide, flat expanse opens up here, remarkable for a mountaintop site.
• A close-up view of the Tenshudai: From the Honmaru ruins you can look directly up at the Tenshudai, making the castle's core layout easy to grasp.

Quick visit: about 5 min / Unhurried: about 20 min

🗺 Address: Shimotoyoura, Azuchi-cho, Omihachiman, Shiga Prefecture
🚶 Access: From the Ninomaru ruins, return to the main path and continue toward the Tenshudai.

Rating: Historical value ★★★ / Visual appeal ★★ / Experience value ★★

• An imperial visit: Based on the foundation-stone layout, some researchers propose a reconstruction resembling the Seiryōden at Kyoto's Imperial Palace, suggesting the palace may have been built with a visit from the emperor in mind — though this theory remains disputed and research continues.

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• The Tenshudai's stone walls: Stone walls roughly 2 meters high enclose the Tenshudai.
• Pillar bases: The pillar bases that once supported the tower are still lined up here, offering a clue to the scale of the original building.
• The view through the trees: From the Tenshudai site, you can see farmland and the Nishinoko ("West Lake") area through gaps in the trees. Today the site is surrounded by trees, but when the tenshu tower stood here, the view may have been considerably wider.
• The mystery of the central pillar: Instead of a normal pillar base at the center, excavators found a hole — raising the possibility that a post was set directly into the ground, and leaving an unresolved structural mystery to this day.

See more panoramic photos here (Shukakubu edition — 13 photos)

Quick visit: about 10 min / Unhurried: about 30 min

🗺 Address: Shimotoyoura, Azuchi-cho, Omihachiman, Shiga Prefecture
🚶 Access: About a 20-minute walk from JR Biwako Line's Azuchi Station to the entrance, then another 25–30 minutes from the entrance to the Tenshudai site — plan for roughly 45–50 minutes total from the station.

Rating: Historical value ★★★ / Visual appeal ★★★ / Experience value ★★★

Azuchi Castle Ruins archaeological excavation report / Shinchō Kōki ("The Chronicle of Lord Nobunaga") by Ōta Gyūichi

• A fusion of religion and architecture: Azuchi Castle's tenshu incorporated religious elements never before seen in castle architecture — a genuinely original structure for its time.
• The mystery of the central pillar: A castle tower's center should normally have a great central pillar resting on its own base stone, but no base stone was found here — only a hole. It's possible the post was set directly into the ground, and this remains one of Azuchi Castle's unsolved mysteries.
• The same scale as Himeji Castle: Research indicates the Tenshudai is roughly the same size as the base of Himeji Castle's keep. In person it feels more compact than you'd expect, but imagining a 32-meter structure rising from this footprint gives a sense of how imposing it must have been.