The Reconstructed Castle Tower
The present Osaka Castle Tower was reconstructed in 1931 using a steel-reinforced concrete structure. Built on the stone foundation of the Tokugawa-period castle tower, its exterior was designed to evoke the appearance of the castle during the era of Toyotomi Hideyoshi.
The tower now serves as the Osaka Castle Museum, where visitors can learn about Toyotomi Hideyoshi, Osaka Castle, and the history of Japan. In 1997, the reconstructed tower was registered as a Tangible Cultural Property of Japan.
One of Japan’s Famous Castles
Osaka Castle is sometimes counted among Japan’s “Three Great Castles,” together with Nagoya Castle, Himeji Castle, and Kumamoto Castle. Its imposing scale, distinctive architecture, and long history make it an important destination for visitors from Japan and around the world.
History of Osaka Castle
The Area Before Osaka Castle
The Uemachi Plateau, where Osaka Castle stands, was historically an important transportation area. The Yodo River and its waterways once flowed nearby, creating natural geographical advantages for defense and transportation.
The surrounding area also contains archaeological remains from ancient Japan, as well as numerous temples and shrines, reflecting its long history as an important center of life and culture.
Ishiyama Hongan-ji and the Origins of Osaka Castle
During the late Sengoku period, Ishiyama Hongan-ji stood on the site. Following the peace agreement that ended the Ishiyama War in 1580, the temple complex was destroyed by fire.
Toyotomi Hideyoshi subsequently selected the site for his new castle and began construction of Osaka Castle in 1583.
Toyotomi Osaka Castle
Construction began in 1583 under Toyotomi Hideyoshi, and Osaka Castle became the political center of the Toyotomi regime. The castle was developed in several stages, with the main compound, secondary compounds, outer areas, and residences for feudal lords gradually being constructed.
The Toyotomi-period castle featured enormous buildings, including a grand palace complex known as Senjōshiki, as well as long corridors and other magnificent structures. Osaka Castle served not only as a powerful fortress but also as a symbol of Toyotomi political authority.
Reconstruction During the Edo Period
Osaka Castle fell during the Siege of Osaka in 1615. The Tokugawa shogunate subsequently rebuilt the castle between 1620 and 1629.
The reconstruction introduced enormous stone walls, moats, turrets, and other defensive structures. The Tokugawa castle differed considerably from the original Toyotomi castle, and much of the earlier castle was buried beneath the new construction.
Surviving Historic Structures
Several structures from the Edo-period castle survive today, including turrets, gates, and stone walls. A comprehensive academic survey conducted in 1959 confirmed that these visible historic remains were associated with the Tokugawa reconstruction.
Modern Reconstruction
Many buildings at Osaka Castle were lost over the centuries, including through fires and wartime damage. The present castle tower was reconstructed in 1931 and has since become one of Osaka’s most recognizable landmarks.
The Location and Structure of Osaka Castle
Osaka Castle stands at the northern end of a plateau, with low-lying areas surrounding it on three sides. The Yodo River and its tributaries once provided natural defensive advantages and also supplied water to the castle’s moats.
The castle visible above ground today largely reflects the Tokugawa-period reconstruction. However, the basic arrangement of some moats and gates is thought to retain similarities to the layout established during the Toyotomi period.
Toyotomi Osaka Castle
Toyotomi Hideyoshi’s Osaka Castle was designed as a concentric-style castle, with the main compound at its center and additional fortified compounds arranged around it.
The castle was protected by inner and outer moats. Hideyoshi also designed the castle tower so that it could be seen prominently from the surrounding city, making the castle an important feature of Osaka’s urban landscape.
The Main Compound
The main compound included several elevated sections and fortified areas. Because castle-building techniques were still developing, the original design relied on layered terrain and defensive platforms rather than only extremely high stone walls.
The Secondary Compound
The secondary compound featured large defensive structures around its entrances. Archaeological excavations have revealed evidence of substantial defensive earthworks and protected entrances known as umadashi.
Defensive Measures in the South
The southern side of Osaka Castle was particularly important from a defensive perspective because it connected directly to the surrounding plateau. Defensive earthworks and Sanada Maru, a fortified position associated with Sanada Nobushige, were used to strengthen this vulnerable area.
The southern approach became an important battlefield during the Siege of Osaka.
Tokugawa Osaka Castle
After the destruction of the Toyotomi castle, the Tokugawa shogunate rebuilt Osaka Castle under the overall supervision of Tōdō Takatora.
The project involved rebuilding the stone walls and moats and constructing a new castle tower and other structures. The scale of the project reflected the advanced castle-building techniques of the Edo period.
Reconstruction Through Tenka-Bushin
The rebuilding project continued for approximately nine years. Although the overall castle area was reduced compared with the earlier Toyotomi fortress, the new castle featured enormous defensive works.
The outer moat reached approximately 90 meters in width, while the eastern stone wall of the main compound reached approximately 32 meters above the bottom of the moat, making it one of the highest castle stone walls in Japan.
Turrets and Tamon Turrets
The Tokugawa-period castle had 12 three-story turrets and 15 two-story turrets. Tamon turrets were also arranged around the main compound and Yamazato Compound, creating an extensive defensive network.
The History of the Castle Towers
Osaka Castle has had three major castle towers associated with the 1585 Toyotomi period, 1626 Tokugawa period, and 1931 modern reconstruction. Although their appearances differed, the present tower stands on the stone foundation of the Tokugawa-period castle tower.
The Toyotomi Castle Tower
The Toyotomi castle tower, completed in 1585, was known for its dramatic black-lacquered exterior and gold-leaf roof tiles. A luxurious Golden Tea Room was reportedly located on the top floor, reflecting the splendor of Hideyoshi’s era.
The tower was destroyed during the Siege of Osaka in 1615.
The Tokugawa Castle Tower
The Tokugawa-period castle tower was completed in 1626. It was a five-story, six-level structure whose arrangement was influenced by Edo Castle.
However, the tower was destroyed by lightning in 1665 and was never rebuilt during the Edo period.
The 1931 Reconstruction
The present castle tower was reconstructed in 1931 using reinforced concrete. Its exterior was designed to evoke the appearance of the Toyotomi-period castle, while the interior was developed as a museum.
Today, the tower introduces visitors to the history of Toyotomi Hideyoshi and Osaka Castle and provides an observation deck overlooking Osaka City.
Historic Structures and Remains
Important Buildings
Several historic structures and remains can be seen within Osaka Castle, including:
Otemon Gate
Enshōgura Gunpowder Storehouse
Tamon Turret, Sengan Turret, and Inui Turret
Ichiban Turret and Rokuban Turret
Kinzo Treasury
Kinmeisui Well House
Many of these structures are designated Important Cultural Properties of Japan. The Kōraimon Gate of Sakuramon Gate was reconstructed in 1887 and is also protected as an Important Cultural Property.
The Stone Walls and Their Hidden History
The enormous stone walls of Osaka Castle were built using granite transported from various parts of Japan. Stone was quarried from islands in the Seto Inland Sea, the Rokko Mountains, and even areas of present-day Fukuoka Prefecture.
Many stones bear marks carved by feudal lords and workers to identify ownership, construction responsibilities, or work groups. These marks provide fascinating traces of the castle’s construction history.
The Giant Takoishi Stone
The largest individual stone within Osaka Castle is known as Takoishi, or “Octopus Stone.” It is estimated to weigh approximately 130 tons.
The massive stone was transported under the direction of Ikeda Tadatsugu, lord of the Okayama domain in Bizen Province. Its enormous scale is one of the most impressive sights within the castle grounds.
Cultural Properties of Osaka Castle
Important Cultural Properties
Thirteen structures at Osaka Castle are designated as Important Cultural Properties of Japan. They include:
Otemon Gate — originally constructed in 1628 and repaired in 1848
Tamon Turret — repaired in 1848
Sengan Turret and Inui Turret — constructed in 1620
Enshōgura Gunpowder Storehouse — constructed in 1685
Kinzo Treasury — constructed in 1625
These structures provide valuable evidence of the architectural techniques and defensive design of Osaka Castle during the Edo period.
Registered Tangible Cultural Property
The present Osaka Castle Tower, reconstructed in 1931, is also protected as a Registered Tangible Cultural Property. Although its exterior evokes the historic castle, the interior functions as a museum.
Special Historic Site
The ruins of Osaka Castle were designated a Special Historic Site in 1955, providing protection for the castle’s historic remains.
Osaka Castle Museum
The Osaka Castle Museum occupies the interior of the iconic castle tower in Osaka Castle Park. It contains numerous historical materials and exhibitions introducing Toyotomi Hideyoshi, Osaka Castle, and Japanese castle culture.
The observation deck offers wide-ranging views across Osaka City, making the tower both a cultural attraction and a scenic viewpoint.
The Reconstruction of the Castle Tower
In 1925, the Toyohōkan building constructed on the castle’s main compound during the “Great Osaka Memorial Exhibition” attracted approximately 700,000 visitors. Its popularity encouraged Osaka Mayor Hajime Seki to pursue the reconstruction of the castle tower.
The reconstruction was approved as a commemorative project for the enthronement ceremonies of Emperor Shōwa and was funded through donations from Osaka citizens.
The new tower used a steel-reinforced concrete structure and included one of Japan’s latest elevators at the time. Designed by Shigeharu Furukawa of the Osaka Municipal Civil Engineering Bureau, its exterior was based on depictions of the castle in screens showing the Siege of Osaka and was intended to evoke the age of Toyotomi Hideyoshi.
Construction was completed in October 1931, giving Osaka Castle a new role as a symbol of the city.
The Castle Museum Opens
The reconstructed tower opened as a museum focusing on Toyotomi Hideyoshi and the history of Osaka. Materials from the Osaka Municipal Civic Museum in Tennoji Park were transferred to the new museum, enriching its collections.
The observation deck, with its views across the Osaka Plain, also became a major attraction.
Wartime Restrictions and Damage
From 1937, photography from the castle tower was restricted due to wartime regulations, and the museum was closed during World War II.
During the Osaka air raids in 1945, parts of the castle’s stonework were damaged, although the main structure of the reconstructed tower avoided severe damage.
Postwar Restoration
After the war, Osaka Castle was eventually returned to the city in 1948 following the occupation period. Osaka Castle Park was expanded, and the museum reopened to visitors.
The Heisei Renovation
From 1995 to 1997, the castle tower underwent a major renovation. The work included seismic reinforcement and repairs to the exterior, improving the building’s safety and preserving its appearance for future generations.
The Castle Tower Today
Today, Osaka Castle Tower functions as a museum introducing the history and culture of Osaka. Exhibitions explain the life of Toyotomi Hideyoshi and the development of Osaka Castle, while the observation deck provides panoramic views of the city.
Osaka Castle Park also contains historic buildings, gardens, moats, stone walls, and walking paths, making it a popular destination for both sightseeing and leisurely exploration.
Inside the Osaka Castle Tower
Visitors normally travel between the first and eighth floors using the stairways. An elevator is also available between the lower castle platform and the various floors for visitors with mobility needs and older visitors.
The staircases feature a double-spiral design that separates ascending and descending traffic. The handrails use easy-to-process artificial stone and feature streamlined Art Deco-inspired forms.
8th Floor — Observation Deck
The eighth floor serves as an observation deck offering views of Osaka Castle and the surrounding city. The deck is accessible to wheelchair users and also includes a museum shop.
Eight cranes are depicted in gold maki-e lacquerwork on the observation deck walls, using a technique known as rōiro finishing, which represented advanced craftsmanship at the time of construction.
7th Floor — The Life of Toyotomi Hideyoshi
This floor presents exhibitions about the life of Toyotomi Hideyoshi, introducing his rise to power and his role in the unification of Japan.
6th Floor — Corridor
The sixth floor is a corridor and is normally closed to visitors.
5th Floor — The World of the Siege of Osaka
This floor introduces the Siege of Osaka through painted folding screens, videos, and miniature models, allowing visitors to explore the events of the conflict in an accessible way.
4th Floor — Toyotomi Hideyoshi and His Era
The fourth floor is used for special and temporary exhibitions featuring valuable materials related to Toyotomi Hideyoshi, the Sengoku period, and Osaka Castle.
3rd Floor — Toyotomi Hideyoshi and His Era
The third floor also hosts special exhibitions and displays. Exhibits include reconstructed models of Toyotomi and Tokugawa Osaka Castles and a life-size reconstruction of the famous Golden Tea Room.
2nd Floor — Castle Information Area
The second floor introduces basic information about Osaka Castle and Japanese castles through panels and replicas.
Visitors can also try on replicas of traditional samurai helmets and jinbaori battle coats, offering an interactive introduction to Japanese castle culture.
1st Floor — Castle Tower Entrance
The first floor contains an information counter, museum shop, and theater room. Visitors can obtain information about Osaka Castle and watch videos introducing its history.