The Tokugawa rebuilt Osaka Castle with stone from all over western Japan. Some of it fell off boats, some was never shipped, and some ended up as a park's name sign. Japanese calls them zannen-ishi, "pity stones", and you can still find them.
残念石 zannen-ishiOsaka · Hyōgo · KagawaFacts checked October 2026
You have been up the keep of Osaka Castle and probably stood in front of the Takoishi, the giant stone at the Sakuramon gate. The keep is a modern concrete rebuild. The walls are the real thing, and they are the part this piece is about: not the stones in them, but the ones that were cut, marked and sent for, and never got there.
Why go? Because a stone lying by a river makes the size of the 1620s building project easier to grasp than any wall. The best of these sites is twenty minutes on foot from the Tenjinbashi-suji shopping street, beside a 1907 river lock that is a National Important Cultural Property. What you give up: these are rocks, sometimes behind weathered signs, in places with nothing else to do.
The wall that took 64 daimyō houses天下普請 · tenka-bushin
After the Tokugawa took Osaka in 1615, they rebuilt the castle on top of Hideyoshi's. The work ran from 1620 to 1629. The keep and towers were built by the shogunate itself, but the stone walls and moats were tenka-bushin, work imposed on the daimyō. Osaka City's conservation plan counts 64 daimyō houses, mostly lords from western Japan.
Each lord was given a section and had to quarry, ship and set the stone himself. To keep track, work gangs cut their lord's mark into the stones.
≈12 kmof stone walls
≈2,000kinds of crest marks
50–60,000marked stones
108 tTakoishi, the largest
The Takoishi, "octopus stone", has a face of about 59 square metres, the area of 36 tatami mats, the largest in Japan. It was set in 1624 by Ikeda Tadao and came from Bizen, in today's Okayama, more than 100 km away. Ashiya City's own magazine says the castle is said to contain over a million stones, about half of them from the eastern Rokkō mountains above Ashiya and Nishinomiya.
Almost all of it came by water. That is why the losses happened on rivers and beaches.
Stones in the park, sorted刻印石広場 · Kokuin-ishi Plaza
Inside Osaka Castle Park, across the Gokuraku-bashi bridge over the inner moat, is Kokuin-ishi Hiroba (刻印石広場), "the crest-stone plaza". Large blocks lie on the ground with their marks turned to the path: circles, swastikas, double circles. Be aware that it is a mix. Some are stones that were brought and never used; others were taken out of the walls during later repairs.
It is the easiest place to learn to read the marks before you go looking for them in the walls themselves.
Ask a park guide or staff member: 刻印石広場はどこですか (kokuin-ishi hiroba wa doko desu ka).
Getting there: Osaka Castle Park; Osaka-jōkōen Station (大阪城公園駅, JR Loop Line) is the usual entrance. Cross Gokuraku-bashi on the north side of the keep.
When: The park itself is free and always open. The keep charges ¥1,200 for adults; hours can change by season.
Reality check: The on-site signs are in Japanese. Bring the mark shapes below.
Each mark stood for a daimyō's work gang. The same shapes appear in the castle walls, which is how a loose stone gets traced back to its builder.
The ones that fell overboard毛馬の残念石 · Kema
The best story is at Kema (毛馬), on the Yodo River north of the city centre. The Yodo River office of the national land ministry tells it plainly on its own heritage page. To rebuild Osaka Castle, the shogunate shipped stones from the dismantled Fushimi Castle down the Yodo. The river was narrow and winding, and some stones fell off the boats. They were raised later, during river works, and because they "almost became Osaka Castle", they are called zannen-ishi. They carry marks such as 山 and a square, the same marks found in the castle walls.
The river that dropped them is the reason for everything around them. From 1896 the government re-cut the Yodo, and in 1907 it opened the Kema No. 1 Lock (毛馬第一閘門), a brick-and-concrete lock about 106 metres long that let boats pass between the new channel and the old river into the city. It was designated a National Important Cultural Property in 2008. A memorial to the river works, 10.6 metres tall, went up after they were largely finished in 1909. The stones sit near it, on the ministry's heritage trail along with the old lock gates and a small arch bridge.
Walk along the levee and you reach a monument to the poet Yosa Buson, who was born in Kema village in 1716. Set up in 1978, it reproduces in his own handwriting a line from a poem of 1777: 春風や堤長うして家遠し, "spring breeze; the levee is long, home is far". You are standing on that levee.
If you can't find them, ask anyone walking a dog: 残念石はどこですか (zannen-ishi wa doko desu ka).
Getting there: Osaka City Bus to Kema-bashi (毛馬橋), or about 20 min on foot from Tenjinbashisuji 6-chōme Station (天神橋筋六丁目駅) by one guide's estimate · area address 北区長柄東3丁目3
When: Riverside park; go in daylight.
Reality check: Sources disagree on how many stones there are, and visitors report the explanation board is weathered. No shops on the levee; bring water.
The stones, the lock and the poet are all on one stretch of levee. The ward line runs between the stones and the poem.
Left on the beach東六甲採石場 · Ashiya
If Kema is about loss in transport, Ashiya is about stones that never left. The eastern Rokkō quarries above Ashiya and Nishinomiya supplied, by Ashiya City's estimate, about half the castle's stone. Workers did not cut from bedrock; they split the rounded granite boulders that litter these slopes, using rows of wedges. The holes they drilled for the wedges, yaana (矢穴), are still visible.
The field began with a teenager. In 1968 Ogura Kōichi, a student at Ashiya High School, found a crest-marked stone in the hills. Today Ashiya City publishes a map of 15 public viewing spots. The most striking: wedge-holed stones still lying in the bed of the Miyagawa river, about 60 metres south of the Hama-uchide bridge (浜打出橋), left at the shore and never loaded. Others stand in the forecourt of the Ashiya City Museum of Art & History.
In nearby Nishinomiya, a quarry worked by the Nabeshima of Saga on Kabutoyama became a National Historic Site in 2018, and the city runs quarry tours about three times a year.
Getting there: Ashiya is on the JR and Hankyu lines between Osaka and Kobe. Use the city's viewing-spot map; the river and museum spots are in town, the quarries are on hiking trails.
When: Town spots any time. Quarry tours are scheduled by Nishinomiya City.
Reality check: The crest stones in the hills mean real hiking. The town spots are quick but small.
Three odd endings小豆島 · 舞子 · 2027
Shōdoshima. The island in the Inland Sea has the national historic site of the Osaka Castle stone quarries, first designated in 1972. About 18 quarry sites remain. At Iwagatani, worked by the Kuroda of Fukuoka, a roadside station keeps a free museum of left-over stones. It is a day trip from Osaka at least.
Maiko Park, Kobe. In 2001 the park put up a large stone carved with its name. In July 2022 a researcher at the Nara National Research Institute for Cultural Properties identified it from images as an Osaka Castle wall stone, with crests of the Horio and Yamauchi. It had once sat in a school garden. For 21 years it was a name sign.
Yokohama, 2027. Osaka Prefecture says its garden at the GREEN×EXPO 2027 in Yokohama, 19 March to 26 September 2027, will display zannen-ishi. Four hundred years late, some of them will finally travel.
The stones were dropped in a decade and found again over four centuries, most of them recently.
The honest part
These are rocks. Without the story, the Kema stones look like landscaping and the park plaza looks like a storage yard. Read before you go.
Not every "zannen-ishi" is one. The castle plaza mixes unused stones with ones removed in later repairs. The general story of quarried stones lost in transport and the Kema story of recycled Fushimi Castle stones are not the same thing. The year the Kema stones were raised is not recorded on the official page, and nobody agrees on how many there are.
Some sites move. A zannen-ishi beside a prefectural road in Kizugawa, Kyoto, was flagged in 2020 for relocation because of a bypass plan, which is why it is not in this guide. Ōyamazaki is often listed too, but no official location could be found.
Kema is a quiet levee. There is no café, and the explanation boards are in Japanese and partly faded.
If you only have one day
Osaka Castle Park. Find the Takoishi inside the Sakuramon gate.
Cross Gokuraku-bashi to the crest-stone plaza. Learn the marks.
Walk the outer walls and spot the same marks in place.
Train to Tenjinbashisuji 6-chōme. Lunch on the Tenjinbashi-suji shopping street.
Walk north to Kema, about 20 minutes. The memorial, the stones, the 1907 lock.
Along the levee to the Buson monument. Read the poem where it was written about.
Running late? Skip the outer-wall walk. Keep Kema: the stones in the river are the reason for the day. With a second day, take the train to Ashiya for the riverbed stones.