CastleMountain castle (yamajiro)Next 100 Fine Castles No. 158
What makes this castle distinctive
Before Azuchi Castle was ever built, Miyoshi Nagayoshi lined this mountain with stone walls and ruled the realm while looking out over Kyoto and the lands around it.
Why?
Stone walls were used in many of Iimori Castle's baileys, and Shijonawate City describes it as a rare example of a heavily stone-walled castle that came before Oda Nobunaga's Azuchi Castle. From 1560 until his death in 1564, Miyoshi Nagayoshi made it his home and ruled the five home provinces around Kyoto and much of Shikoku from here. The summit offers a 270-degree view over the lands he governed, from Kyoto to Settsu, Kawachi and Izumi.[1][4][9]
Around baileys throughout the castle. Surveys suggest the east side in particular may once have been faced with stone throughout.
What to look at
Walls of stones stacked almost vertically, some built in several tiers.
Why it's interesting
Iimori is one of the earliest castles to use stone walls. Rather than serving as bases for buildings, as in later castles, the walls may have held back built-up earth and made the castle look imposing.[1][4]
Can you see it?
Visible from outsideSome walls can be seen from the hiking trails; others are hidden by vegetation.
The baileys around the summit of Mt. Iimori (314 m).
What to look at
The Osaka Plain spreading to the west, and the view north toward Kyoto.
Why it's interesting
Daito City explains that Nagayoshi developed Iimori as a base with a 270-degree view over everything then considered "the realm," from Kyoto to Settsu, Kawachi and Izumi. Below to the west lay Lake Fukano, and the area was a crossroads of highways and Yamato River shipping routes.[4][9]
Can you see it?
Visible from outsideThe summit area is open to walk around.
The ridge running north and south from the summit, with the Gotaizuka, Takayagura and Senjojiki baileys among others, from north to south.
What to look at
The chain of leveled baileys and the trenches, earthen bridges and gateways (koguchi) between them.
Why it's interesting
The castle covers about 700 m north to south and 400 m east to west, which Shijonawate City calls one of the largest in western Japan, with more than 70 baileys. The Gotaizuka bailey to the north is said to be where Nagayoshi's body was temporarily buried after his death.[1][4][12]
Can you see it?
Visible from outsideHiking trails pass the main baileys. A radio transmitter stands on the Senjojiki bailey.
At a glance for visitors
Nearest station
90 min walk from JR Nozaki Station
Climb
Steep climb
Time neededEditors' estimate
Allow half a day (3–4 hours) to climb from the station, explore and come back down.
Admission
Not confirmed
Hours
9:30–17:00
Access
Open to visitors
The castle site is woodland explored on hiking trails. Any alteration within the designated area, such as digging, requires permission. The Next 100 Castles stamp is not on the mountain but at the Shijonawate City Museum of History and Folklore, the Shijonawate Outdoor Activity Center, the Daito City Museum of History and Folklore, and Campy Daito (ask staff during opening hours).
Mt. Iimori sits on a ridge branching west from the northern Ikoma Mountains, and several highways met at its foot. Lake Fukano spread out to the west, linking the area by Yamato River boats to Osaka, Sakai and the Seto Inland Sea. The mountain's west, north and east sides are steep; only the south, where the ridge continues to Mt. Ikoma, is gentle, making it hard to attack and easy to defend.[4]
02
Historical record
From Kizawa Nagamasa to Miyoshi Nagayoshi
Iimori Castle first appears in records in 1530 as the residence of Kizawa Nagamasa, deputy governor of Kawachi province and a retainer of Hosokawa Harumoto. It later passed to Yasumi Munefusa, and in November 1560 Miyoshi Nagayoshi moved his base here from Akutagawayama Castle in Takatsuki. Nagayoshi is thought to have rebuilt the castle extensively.[6][1][4]
03
Historical record
Capital of the Miyoshi government, and a cultural salon
From here Nagayoshi governed the five home provinces (Yamato, Yamashiro, Kawachi, Settsu and Izumi) and much of Shikoku, steering the affairs of the Muromachi shogunate. He held power for only a little over four years, but Shijonawate City describes the castle as a kind of capital. Renga poetry gatherings were held here, and after Nagayoshi permitted Christian preaching, 73 of his retainers were baptized in the castle, sparking the spread of Christianity in Kawachi.[1]
04
Tradition
Nagayoshi's death, kept secret for three years
In 1564 Nagayoshi died in the castle at the age of 42. His death was kept secret for three years, and tradition says his body was temporarily buried in the Gotaizuka bailey. The castle later passed through other hands, including members of the Miyoshi clan, and is said to have fallen and been abandoned in 1576.[1][12]
05
Historical record
No buildings, but walls and baileys remain
None of the castle's buildings survive, but baileys, stone walls, trenches, earthen bridges, ramparts, gateways and kirigishi (artificially steepened slopes) remain in good condition around the summit. In 1930 a hilltop leisure park opened here, with lodges, a tent village and a restaurant, but it appears to have closed after about ten years as the war intensified.[1][4][10]
06
Historical record
Surveyed and made a National Historic Site
Daito and Shijonawate cities began a joint survey in fiscal 2016 and showed the site to be a landmark in the history of Japanese castle building. It was named one of the Next 100 Fine Castles of Japan in 2017 and designated a National Historic Site on October 11, 2021, covering about 630,000 square meters.[6][7][1]
A Sengoku-period mountain castle with no keep; no buildings survive.
The site today
The remains lie in the woods of Mt. Iimori, crossed by hiking trails. A statue of Kusunoki Masatsura, the temple Nankoji and a radio transmitter stand near the summit.
Main buildings
Key facts
Type
Castle
Setting
Mountain castle (yamajiro)built on a mountain; expect a climbEditorial article
Period
Medieval (c.1185–1570s)Editorial article
Keep (tenshu)
No keep was builtthe castle never had a keepEditorial article
Built by
Kizawa Nagamasa, Miyoshi NagayoshiJapan Castle Foundation
National Historic Site (Iimori Castle Ruins) (2021)Editorial article
Selection
Next 100 Fine Castles No. 158Japan Castle Foundation
Visiting
Access
Open to visitors
The castle site is woodland explored on hiking trails. Any alteration within the designated area, such as digging, requires permission. The Next 100 Castles stamp is not on the mountain but at the Shijonawate City Museum of History and Folklore, the Shijonawate Outdoor Activity Center, the Daito City Museum of History and Folklore, and Campy Daito (ask staff during opening hours).
JR Nozaki StationJR Gakkentoshi Line (Katamachi Line)
about 90 min walk · Steep climb
Take the hiking trail from Nozaki Kannon (Jigen-ji temple) to the summit. Daito City gives 90 minutes uphill.[5]
Checked: 2026-10-03
JR Shijonawate StationJR Gakkentoshi Line (Katamachi Line)
about 100 min walk · Steep climb
Take the hiking trail from Shijonawate Shrine. Daito City gives 100 minutes uphill. Shijonawate City's guide map shows both the Iimoriyama hiking course and a castle approach course.[5][3]
Checked: 2026-10-03
Tatsuma bus stop, Kintetsu BusFrom JR Suminodo Station, buses bound for Ikoma Tozanguchi
about 40 min walk · Some climbing
Walk north from the stop to the castle site; Daito City gives about 40 minutes.[5]
Checked: 2026-10-03
Hours and admission
Shijonawate City Museum of History and Folklore (stamp and Iimori Castle displays)
Hours
9:30–17:00
Closed
Mondays (the next day if Monday is a national holiday)
Daito City Museum of History and Folklore / Campy Daito (stamp and castle seal cards)
Hours
Not confirmed
Closed
Not confirmed
Admission
Castle seal cards 300 yen each (price at launch in 2020)[8]
Checked: 2026-10-03
By car / parking
The Iimori Castle Ruins parking lot in front of Campy Daito can be used (capacity and fees not confirmed). There are coin-operated lots near Suminodo and Shijonawate stations.[5]
Checked: 2026-10-03
Grounds opening hours
Not confirmedChecked: 2026-10-03
Time neededEditors' estimate
Allow half a day (3–4 hours) to climb from the station, explore and come back down.
Steps, slopes and footing
A hike up a 314 m mountain on unpaved trails.[4][5]
Wheelchairs and strollers
Being a mountain trail, it is not realistically wheelchair accessible (no official statement).Checked: 2026-10-03
Toilets and rest
Not confirmed
English signs / audio guide
Not confirmed
Seasons
Not confirmed
Photography
Not confirmed
Works, closures and restrictions
Alterations within the designated area (digging, cutting trees and so on) require an application.[4]Checked: 2026-10-03
City museum displaying and explaining finds from Iimori Castle and its satellite Tawara Castle, with the Next 100 Castles stamp. It lies between JR Shijonawate and Shinobugaoka stations.[2][3]
Temple at the trailhead on the Nozaki side, known for the Nozaki Mairi pilgrimage fair held for a week from May 1. About 10 minutes' walk east of JR Nozaki Station.[9]
Checked: 2026-10-03
Editors' guide
An editorial guide based on sources and confirmed information — not a first-hand visit report.
Who will enjoy it
Good for anyone who wants a hike and a castle in one, people interested in the history of stone walls, and those following Miyoshi Nagayoshi, a ruler of the realm before Nobunaga. Combine it with Akutagawayama Castle in Takatsuki to compare his two residences.
What makes it interesting
First, look for the nearly vertical stone walls: early walls predating Azuchi Castle, still standing in the woods, are what makes this castle special. Then take in the Osaka Plain from the baileys near the summit and see for yourself why Nagayoshi based himself here.
Before you go
The castle is on a mountaintop, and the climb from the station takes about 90–100 minutes according to Daito City. The stamp is not on the mountain, so visit a museum before or after your hike, keeping closing days in mind. Many photos used here date from around 2006–2008, and the site may look different today.
Ways to enjoy it
Climb from Nozaki and descend to Shijonawate, linking the temple and shrine at each end, for a varied hike. Seeing the excavated finds at the Shijonawate museum first helps you imagine life on the mountain.
Photos
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Open questions
The Japan Castle Foundation dates the castle to the Kyoroku era (1528–32); Daito City says it first appears in records in 1530 as Kizawa Nagamasa's residence. Some accounts trace it back to the 14th century.
Daito City's pages differ on hiking time: 90–100 minutes uphill on its access page, about one hour on its sightseeing page.
The temporary burial of Nagayoshi's body in the Gotaizuka bailey is tradition. The castle's fall and abandonment in 1576 could not be confirmed on the cities' official pages and relies on secondary sources.
The Japan Castle Foundation list shows no designation, but the site became a National Historic Site in 2021.
Parking capacity and fees, toilets on the mountain, museum admission, and English information could not be confirmed.
ブレイズマンPublic domainWikimedia Commons
