亀山城（丹波） · Tamba-Kameyama-jo
Where Akechi Mitsuhide set out to assassinate Nobunaga — and where a bureaucratic error later demolished the wrong castle, erasing the main tower forever.
#170 — Continued 100 CastlesBus also available
The castle site is now the headquarters of the Omoto religious organization, which allows visitors to view the remaining tower from outside. Interior access is restricted.
Tamba-Kameyama Castle is a must for Sengoku history enthusiasts interested in Akechi Mitsuhide and the Honnoji Incident. The castle's unusual status as a living religious headquarters (Omoto) adds an eerie layer: the place that launched Japan's most dramatic political assassination is now a spiritual compound.
Tamba-Kameyama Castle was the domain seat of Akechi Mitsuhide — the general who assassinated Oda Nobunaga at Honno-ji Temple in 1582, one of the most dramatic events in Japanese history. Mitsuhide marched from this castle toward Kyoto with his army before turning and attacking Honno-ji. The castle thus played a direct role in the event that ended Nobunaga's unification campaign.
The castle site is uniquely occupied by the Omoto (Oomoto) religious organization — a Shinto-derived new religion founded in 1892. The remaining castle structures, including a surviving stone-walled turret base, are incorporated into the Omoto complex. This unusual combination makes Tamba-Kameyama unlike any other castle site in Japan.
One original turret (yagura) base with stone walls survives from the Momoyama-period castle — a direct physical connection to Akechi Mitsuhide's construction. The stone wall style and construction quality date to the late 16th century.
Visitor Tip
The castle is now within the Omoto religious compound — access is restricted. View the surviving stone walls and turret base from the perimeter. The Hozu River gorge between Kameoka and Arashiyama was controlled by this castle.
hirajiro
Flatland castle (built on a low hill on the edge of the Kameoka basin, using the Oi River and lowland terrain as natural moats)
renkaku
Compound style — multiple compounds with moats
No tenshu survives — the castle was ordered partially demolished in 1608 after a bureaucratic misunderstanding. One original stone-walled turret base remains.
nozurazumi — Natural stone stacking — late Momoyama period ishigaki construction typical of Kinai region castles of the 1580s–1590s
Stone walls were constructed by Akechi Mitsuhide in the 1580s. The surviving turret base stone walls show the quality of late 16th-century castle construction.
Water moats surrounded the castle compounds. Most moat traces are now absorbed into the religious compound landscape.
Kameoka Basin Position
The castle controlled the Kameoka basin — the agricultural heartland of Tamba Province and the gateway between Kyoto and the Sanin region.
Oi River Natural Defense
The Oi River provided a natural barrier on the castle's western side and gave the castle control of the river route into the capital.
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 — Tamba-Kameyama Castle
Tamba-Kameyama Castle's main defensive value was its control of the Kameoka basin approaches to Kyoto. Capturing the castle would have given an attacker control of the western gateway to the capital and the Sanin Road trade route.
Akechi Mitsuhide constructs Tamba-Kameyama Castle after Nobunaga assigns him the Tamba pacification campaign.
Mitsuhide's army marches from Tamba-Kameyama ostensibly to support Nobunaga's Chugoku campaign. Instead, they attack Honno-ji. Within days Mitsuhide is defeated at the Battle of Yamazaki and killed.
Tokugawa shogunate officials misread a document authorizing 'demolition of Kameyama Castle' and Tamba-Kameyama is partially torn down in a bureaucratic error. The main tower is never rebuilt.
The Omoto religious organization acquires the castle site and establishes its headquarters here.
The Japanese government suppresses the Omoto organization in a major crackdown. Omoto reestablishes after 1945.
The 2020 NHK Taiga Drama featured Akechi Mitsuhide as its protagonist — directly depicting his time at Tamba-Kameyama Castle before the Honnoji Incident.
Year-round. Autumn foliage is beautiful in the Kameoka basin.
30–45 minutes (exterior viewing) + optional Hozu River boat tour (2 hours)
The Hozu River boat tours from Kameoka Station to Arashiyama are one of Kyoto's underrated attractions and pass through the river valley that Tamba-Kameyama Castle controlled.
Free Entry
The castle site is now the headquarters of the Omoto religious organization, which allows visitors to view the remaining tower from outside. Interior access is restricted.
Exterior viewing available during daylight hours.
二条城 · Nijo-jo
📍 Kyoto — Kansai
The castle where the shogunate both began and ended — Nijo is a palace of power politics, famous for floors that sing and paintings that dazzle, not for towers or battles.
福知山城 · Fukuchiyama-jo
📍 Kyoto — Kansai
Built by the man who killed Nobunaga — Akechi Mitsuhide's castle in Tamba, rehabilitated from villain to tragic hero by a 2020 TV drama.
田辺城 · Tanabe-jo
📍 Kyoto — Kansai
Where a besieging army of 15,000 stood down because the Emperor wanted to save the defender's classical literary knowledge — Japan's most culturally remarkable castle siege.
The nearest station is Kameoka Station (JR Sanin Main Line from Kyoto — approximately 20 minutes). It is approximately a 15-minute walk from the station. Bus service from Kameoka Station to castle area. Parking: Limited parking near the castle site. Accessible with a JR Pass.
Tamba-Kameyama Castle is free to enter. The castle site is now the headquarters of the Omoto religious organization, which allows visitors to view the remaining tower from outside. Interior access is restricted.
Tamba-Kameyama Castle is a must for Sengoku history enthusiasts interested in Akechi Mitsuhide and the Honnoji Incident. The castle's unusual status as a living religious headquarters (Omoto) adds an eerie layer: the place that launched Japan's most dramatic political assassination is now a spiritual compound.
Tamba-Kameyama Castle is open 09:00 – 17:00 . Exterior viewing available during daylight hours.
Plan on spending 30–45 minutes (exterior viewing) + optional Hozu River boat tour (2 hours) at Tamba-Kameyama Castle. The Hozu River boat tours from Kameoka Station to Arashiyama are one of Kyoto's underrated attractions and pass through the river valley that Tamba-Kameyama Castle controlled.