Toyotomi Stone Wall Museum: the castle under the castle
Every stone wall standing in Osaka Castle Park today was built by the Tokugawa. Hideyoshi's original castle is underground. This museum, opened in April 2025, lets you see part of it.
It is a 2-minute walk southeast of the Main Tower, and your Main Tower ticket gets you in.
Why the walls were buried
Toyotomi Hideyoshi began building Osaka Castle in 1583. His son Hideyori lost it to Tokugawa Ieyasu in the Summer Siege of 1615, and the castle burned.
In 1620 the Tokugawa started a new castle on the same spot. They piled about 6 meters of earth over the old one and built new walls on top. The museum's leaflet puts it plainly: the aim was to erase the authority of the Toyotomi.
The buried walls were forgotten for over 300 years. A wall of small, rough stones found under the castle in 1959 was the first clue. In 1984 an excavation uncovered the wall now shown in the museum.
Timeline
| Year | What happened |
|---|---|
| 1583 | Hideyoshi begins building Osaka Castle |
| 1598 | Hideyoshi dies |
| 1615 | The castle falls in the Summer Siege of Osaka and burns |
| 1620 | The Tokugawa begin rebuilding and bury the old walls |
| 1959 | A "mystery wall" is found under the castle, later shown to be Toyotomi work |
| 1984 | Excavation uncovers the wall shown in the museum |
| 2025 | The museum opens on April 1 |
What you see inside
Hideyoshi's inner citadel had three levels. The wall in the museum belongs to the top level, the Tsume-no-maru: the private quarters of Hideyoshi, his wife, his son Hideyori and Hideyori's mother Yodo-dono.
- Rough, natural stones. The wall is built in the nozura-zumi style, with stones that were barely shaped. Compare it with the huge, cut stones of the Tokugawa walls outside.
- Long corner stones. At the corners, long rectangular stones are laid with their long and short sides alternating (sangi-zumi), to keep the corner strong.
- Stones from old temples. Some stones were taken from older buildings and reused.
- Burn marks from 1615. Some stones still show scorch marks from the fire when the castle fell.
The museum also has a theater and an illustration of how Hideyoshi's inner citadel looked.
Hours, tickets and location
- Hours: 9:00 to 18:00, last entry 17:30. Closed over the New Year holidays. It may also close for maintenance.
- Ticket: your Osaka Castle Main Tower ticket. Ways to buy tickets
- Location: about a 2-minute walk southeast of the Main Tower. See it on the map
Last entry is the same 17:30 as the Main Tower. If you arrive late in the day, decide which one you want to see first.
See the stone walls outside too
All the walls standing in the park were built by the Tokugawa from 1620, using stones from as far away as Shodoshima island and Kyushu. More than 60 daimyo families were ordered to supply them, and many stones still carry their marks. You can see a collection of these marked stones at the Yamazato-maru, just north of the Main Tower.
Outside the park, two more pieces of Hideyoshi's walls can be seen from the street: at the Dawn Center and at Otemon Gakuin Elementary School, both a short walk west of the castle.
Questions
What is the Toyotomi Stone Wall Museum?
An underground museum at Osaka Castle that shows a stone wall from Toyotomi Hideyoshi's original castle. The Tokugawa buried it under about 6 meters of earth when they rebuilt the castle in the 1620s. It was found in 1984 and the museum opened on April 1, 2025.
Do I need a separate ticket for the Stone Wall Museum?
No. You can enter with your Osaka Castle Main Tower ticket.
Where is the Toyotomi Stone Wall Museum?
Inside Osaka Castle Park, about a 2-minute walk southeast of the Main Tower.
What are the opening hours?
9:00 to 18:00, with last entry at 17:30. It closes over the New Year holidays and may close for maintenance.
Are the stone walls you see around Osaka Castle today from Hideyoshi's time?
No. Every stone wall standing in the park today was built by the Tokugawa from 1620. Hideyoshi's walls survive only underground, which is why this museum matters.
Toyotomi Hideyoshi and Osaka Castle
Written by Kyoya Fujioka. Facts come from the Toyotomi Stone Wall Museum English leaflet, the Osaka Castle Museum leaflet (issued April 1, 2026) and the Osaka Castle Museum map of stone wall sites (issued May 2026).